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Early Greenland Melt Spike Possible as Forecast Calls for Temperatures of up to 50 F Above Average

Greenland — a region vulnerable to the slings and arrows of human-forced climate change — appears set to experience both considerable warming and a significant melt spike this week.

Starting on Wednesday, May 3, a sprawling dome of high pressure is expected to begin to extend westward from the far North Atlantic and out over Iceland. As the high pressure dome builds to 1040 mb over the next couple of days, its clockwise flow will thrust abnormally warm and moist air northward out of the Atlantic. This air-mass is expected first to over-ride eastern Greenland, then run up into Baffin Bay, finally encompassing most of the island and its vast, receding glaciers.

(May 5, 2017 GFS model run as shown by Earth Nullschool is predicted to produce widespread above-freezing temperatures over the surface of the Greenland Ice Sheet. Such warming is expected to be accompanied by rainfall over a number of glaciers. Image source: Earth Nullschool.)

Liquid precipitation is then expected to start falling over southern sections of the Greenland Ice Sheet as temperatures rise to 1-6 C (33 to 43 F) or warmer. Since water contains more latent heat energy than air, such rainfall is likely to produce more melt than would otherwise be caused by a simple temperature rise.

For those of us living in more southerly climes, a temperature of 6 C (43 F) may not sound very warm. But for the northeastern region of Greenland shared by the ZachariaeBrittania, Freja, and Violin Glaciers, such temperatures far exceed ordinary expectations for early May. They are anything but normal. In fact, the building influx of heat is more reminiscent to readings Greenland would have tended to experience during summer — if at all — under past climate averages.

(GFS model predictions for May 4 show widespread liquid precipitation falling over southern Greenland. Image source: Climate Reanalyzer.)

Unfortunately, the new climate presented by human-forced warming is now capable of producing some rather extraordinary temperature extremes. And the anomaly ranges that are predicted for the coming week are nothing short of outlandish.

According to climate reanalysis data, by May 5th, temperatures over northern and eastern Greenland are expected to range between 15 C above average over a wide region and between 20 and 28 C above average in the northeast. For the Fahrenheit-minded, that’s 27 to 50 degrees F above normal. Or the equivalent of a 102 F to 125 F May day high in Gaithersburg, MD.

(An amazing temperature spike is expected to ride up and over Greenland on May 3 to May 5. This warming is expected to produce very extreme above average temperatures for this time of year. Image source: Global and Regional Climate Anomalies.)

Overall excessions for Greenland temperature are also predicted to be quite extraordinary for the day — hitting nearly 9 degrees Celsius (16 F) above average for the whole of this large island. So much warmth extending so far inland and combining with liquid precipitation, if it emerges as predicted in these GFS climate models, is likely to produce a significant early season melt spike — especially over southern and eastern Greenland. In places, these temperatures exceed expected normal summer conditions for Greenland’s glaciers. So it is difficult to imagine a situation where a significant surface melt spike does not occur if these predicted temperatures emerge.

Links:

Earth Nullschool

Global and Regional Climate Anomalies

Climate Reanalyzer

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Hot Climate Conjures Trio of Nasty Halloween Tricks — Heatwaves, Record-Low Sea Ice, Fall Greenland Melt

With each passing year, the effects of human-caused climate change become more and more visible. But for some reason, Halloween appears to be a preferred time for the emergence of various hothouse hobgoblins. In 2012, the Atlantic seaboard was reeling after a vicious strike from Hurricane Sandy. Over the past three years, powerful North Atlantic storms had begun to build at this time of year, setting sights on the UK and Europe. This year, as a hurricane-force low roars toward the Aleutians, the nastiness comes in the form of weird heatwaves, record-low global sea ice coverage, and hints of odd late-fall Greenland melt.

Record Heat Strikes Arctic, U.S.

NASA’s Gavin Schmidt has been warning for months that 2016 will be a global scorcher for the record books. Nowhere has this heat been more apparent than in the Arctic. Halloween only serves to reinforce the rule as today’s temperature departure for the entire region above 66 degrees north latitude hit 5.94 degrees Celsius above average:

global-anomaly-map-halloween

(The extreme Arctic warmth that has already caused so much in the way of climate disruption remains firmly entrenched on Halloween. Image source: Climate Reanalyzer.)

Yesterday, those temperatures exceeded the 6-C-above-normal mark. And later this week, temperatures for the region could approach 6.3 to 6.5 C above average.

These are the average departure ranges for the entire area above the Arctic Circle. Localities within that broader region are hitting as much as 20 C (36 Fahrenheit) or more above average on an almost daily basis, bringing temperatures more typical of the Arctic during late summer than in the middle of fall.

In Barrow, Alaska, Jonathan Erdman reports that Saturday saw the proverbial mercury hit 41 F. This temperature, at about 26 degrees above average, smashed the previous daily high and pushed the latest day Barrow has ever seen a reading above 40 F fully one week forward.

record-temperatures-us

(Daily high and high min temperature records for the U.S. were broken at an alarming rate over the past week, producing a Halloween heatwave. Image source:  NOAA.)

Farther south, the lower 48 is experiencing what Bob Henson over at Weather Underground is calling the Halloween Heatwave. Over the past week alone, nearly 300 daytime high marks were broken. But the measure of record-high minimum temperatures — a key indicator of human-forced warming — is off the charts with 639 total records smashed over the past seven days.

What’s even more odd is a near-total lack of cool temperatures. Bob Henson finds that:

Even more noteworthy than the degree of warmth is the lack of widespread autumn chill. For example, Minneapolis has yet to dip below 36°F as of Friday, October 28. That doesn’t look likely to happen before at least next weekend (November 5 – 6). In records going back to 1873, the latest Minneapolis has ever gone before seeing its first 35°F of the autumn is November 1, way back in 1931. The city’s latest first freeze was on Nov. 7, 1900.

Reinforcing this point, NOAA finds that over the past week just 40 record low high temperatures were achieved (about one-seventh the number of record highs). Meanwhile, record low nighttime temperatures were only achieved in six instances, about one-one-hundredth the rate of record high minimum temperatures! Furthermore, at no location in the U.S. for this week, this month, or even this past year has snow depth achieved a new record high. That’s a pretty ridiculous indicator that the U.S. has reached a rather disturbing climate threshold for heat overall.

Record Low Global Sea Ice Coverage

Even as new warm temperature records were being set with amazing frequency across parts of the Northern Hemisphere, another duo of worrisome indicators were popping up in the Arctic and Antarctic. In the Arctic, the ocean has been loaded up with a ridiculous amount of heat. This heat is preventing the ocean from refreezing, creating various regional barriers to ice formation as the waters ventilate this excess heat into the atmosphere. As a result, Arctic sea-ice extent record lows continue to deepen.

Fall 2016 sea ice extent values — which have consistently lagged behind average daily refreeze rates for most of the season — are now more than 600,000 square kilometers below the previous record set during 2012. It’s, quite frankly, an insane shattering of the previous record low value; a warming-spurred melt that has erased an area of sea ice coverage nearly the size of Texas in just four years.

arctic-sea-ice-jaxa

(Current Arctic sea ice extent values are 6.92 million square kilometers [October 30]. This is 600,000 square kilometers below the previous record low set on the same day during 2012. It is also about 3 million square kilometers below average values seen for this day back during the 1980s. Image source: JAXA.)

The Washington Post this past Friday provided a good article explaining the dynamics involved and highlighted predictions by prominent Arctic researchers that ice-free summers could occur by the 2030s. This is a marked departure from earlier estimates that had put off ice-free summers until the 2050s or even the 2080s. However, it’s worth noting that there’s a decent risk that even these more advanced predictions may prove conservative in the end. Under current trends, ice-free periods for the Arctic Ocean during summer become statistically possible as soon as the early to mid 2020s, and a strong outlier year — where an abnormally warm winter is followed by an abnormally warm summer — could produce such a result even sooner.

On the other side of the world, the Antarctic is also experiencing record-low ranges for sea ice extents. There, regional temperatures are near 4 C above average for the entire Antarctic. Though these departures are not as extreme as those currently seen in the Arctic, they are certainly enough to impact sea ice. Now, sea ice extent values there are at their second lowest ever recorded in the daily measure.

Over recent years, storminess in the Southern Ocean and an expanding fresh water lens running out from Antarctica due to glacial melt have generated a seemingly contradictory expansion of sea ice near Antarctica. This happens because fresh water at the ocean’s surface acts to deflect heat toward the ocean bottom, a feature that has enabled the melting of various glacier undersides in Antarctica. But as the global ocean and atmosphere warm in general, larger melt outflows are necessary to reinforce this surface freshwater lens effect. As a result, we appear to be experiencing a seesaw in Antarctic sea ice extent as a pulse of atmospheric and ocean warming overrides the impact of initial fresh water lensing.

global_sea_ice_extent_zoomed_2016_day_301_1981-2010

(MASIE global sea ice extent shows a severe negative departure through October 28, 2016. Image source: Sunshine Hours.)

The combination of significant sea ice losses in the north and second-lowest sea ice extents in the south has resulted in a global sea-ice measure that is well below anything seen in the past for this time of year. It is also one of the largest global negative sea-ice departures seen for any part of the record for any time of year — even when compared to the extreme period of Arctic sea ice loss during September of 2012.

Halloween Greenland Melt?

In addition to producing heatwaves, new temperature records, and ever more extreme sea ice melt, the odd Halloween warmth appears to also be generating flashes of surface melt over parts of northeastern Greenland. There, over the past few days, temperatures have approached or even exceeded the freezing point as warm winds have blown in from the heating Greenland Strait.

(A warm front crosses over northeastern Greenland on October 27, 2016. The associated warm winds blowing off the heating waters of the Greenland Strait produced near or above freezing temperatures for isolated parts of this section of Greenland. This abnormal warmth appears to have tripped NSIDC’s melt sensor, producing a possible odd late-season melt event for sections of this frozen island. Image source: Earth Nullschool.)

This heat has been enough to trip NSIDC’s Greenland melt indicators for the region of the Zachariæ Isstrøm glacier. These indicators, over the past couple of days, have shown relatively extensive melt in this sector of Greenland. During summer 2016, northeastern Greenland was one of the regions that saw strongest indications of surface melt. Typically isolated by sea ice from warm ocean breezes, northeast Greenland does not usually see such long-lasting periods of surface melt. This is especially true for late October as melt during this time for any portion of the Greenland Ice Sheet is practically unheard of. However, as warm ocean water has advanced further and further north, this region has become more vulnerable to invasions of warm air. And it appears that the melt-forcing effect of this ocean warming for nearby Greenland glaciers may well be extending into fall.

Though unconfirmed by NSIDC, these periods of possible melt have occurred coincident with temperature departures in the range of 10-20 degrees C above average. However, since near or above freezing temperatures have mostly been isolated to the very far northeastern sections of Zachariæ Isstrøm near the coast, it’s likely that any potential and brief periods of melt were located in a more limited band than what has shown up on the NSIDC melt maps for October 27, 28, and 29. That said, as noted above, any surface melt over glaicers in Greenland for this time of year would be very odd and concerning — no matter how isolated.

Nasty Global Warming Tricks for Halloween

Halloween heatwaves, record-low sea ice extents and possible periods of fall Greenland melt are all indicators that human-forced climate change is starting to generate more and more obvious effects. Though the most extreme impacts are hitting remote regions like Greenland, the Arctic and the Antarctic, the related abnormal warmth has filtered into the middle latitudes and is now affecting millions of people across the U.S. And what’s happening in the U.S. is linked to these related warming events on a global scale.

So happy Halloween, everyone. Enjoy the holiday. But remember that if it’s oddly warm where you are, it’s not just a freak warm weather treat, but one of the many and worsening tricks conjured up by global climate change.

Links:

NOAA

The Climate of Gavin

Climate Reanalyzer

Jonathan Erdman

Zack Labe

Earth Nullschool

NSIDC

Sunshine Hours

Half a Kilometer of Ice Gone in Just 7 Years

JAXA

Hat tip to Colorado Bob

Hat tip to DT Lange

Hat tip to June

Record-Hot 2016 Marks the Start of Bad Climate Consequences, Provides “Fierce Urgency” to Halt Worse Harms to Come

“…there is now strong evidence linking specific [extreme] events or an increase in their numbers to the human influence on climate.” — Coumou and Rahmstorf 2012.

“We are confronted with the fierce urgency of now. …We may cry out desperately for time to pause in her passage, but time is deaf to every plea and rushes on. Over the bleached bones and jumbled residues of numerous civilizations are written the pathetic words, ‘Too late.'” — Dr. Martin Luther King, Jr. [emphasis added]

****

2016 is on track to be a record-hot year for the history books. Accumulations of heat-trapping gasses in the range of 402 ppm CO2 and 490 ppm CO2e have pushed the global temperature trend into an inexorable upward rise. Meanwhile, increasingly severe climate change-related events ranging from mass coral bleaching, to glacial and sea ice melt, to tree death, to ocean health decline, to the expanding ranges of tropical infectious diseases, to worsening extreme weather events have occurred the world over. This global temperature spike and related ramp-up of extreme events continued throughout a year that is setting up to follow 2014 and 2015 as the third record-hot year in a row.

(2015 saw a substantial jump in global temperatures. 2016 is also on track to hit new record highs. The above graph, by Gavin Schmidt of NASA GISS, provides a vivid illustration of an inexorable warming trend with 2016 as the hottest year yet. According to Gavin, a strong new record for 2016 appears to be a lock. Image source: Climate of Gavin.)

Now, after NASA’s report showing that September 2016 was 1.13 C hotter than 1880s averages (or 0.91 C hotter than NASA’s 20th-century baseline measure), this year is setting up to be the warmest ever recorded by a wide margin. Overall, the first nine months of 2016 have averaged 1.25 C above 1880s temperatures. Meanwhile, the climate year — which runs from December through November — is tracking 1.26 C above 1880s temperatures during the ten-month period of December to September.

2016 as much as 1.25 C Hotter than 1880s Averages

As a result, it appears likely that 2016 will see temperatures in the range of 1.19 C to 1.25 C hotter than 1880s averages. That’s about 0.1 C hotter than 2015 — which is pretty significant considering the fact that the average rate of decadal warming (the rounded rate of global warming every 10 years) has been in the range of 0.15 C since the late 1970s. This year’s temperatures now appear set to exceed 1998’s values by around 0.35 C — or about one-third of the entire warming total seen since large-scale human greenhouse gas emissions began during the late 19th century. This excession should permanently put to rest previous widely circulated false notions that global warming somehow stopped following the strong El Nino year of 1998.

Many responsible sources are now warning that current temperatures are uncomfortably close to two major climate thresholds — 1.5 C global warming and 2.0 C global warming. At the current rate of warming, we appear set to exceed the 1.5 C mark in the annual measure in just one to two decades. Hitting 2 C by or before mid-century has become a very real possibility. Scientists have been urging the global community to avoid 2 C warming before 2100 (and 1.5 C if at all possible), but the current path brings us to that level of warming in just over 30-50 years, not over the 84 years remaining in this century. And just maintaining current rates of warming without significant added feedbacks from the Earth System would result in Earth hitting close to 3 C warming by 2100 — a level that would inflict severe harm to life on Earth, including human civilizations.

september-of-2016

(According to NASA, September 2016 edged out September 2014 as the hottest September in the 136-year climate record. This occurred while the Equatorial Pacific was flipped into a cool phase, which tends to lower global temperatures. Despite this natural variability-related switch pulling global temperatures down, NASA shows a globe in which few regions experienced below-average temperatures and where the highest concentration of record-warm temperatures are centered near the northern polar region. This display of counter-trend warming and strong polar amplification are both signature effects of human-caused climate change. Image source: NASA GISS.)

Focusing back on 2016, it appears the La Nina that struggled throughout August and early September is again making a decent attempt to form, at least as a weak event. This should tend to pull October, November and December temperatures into the 1 to 1.1 C above 1880s departure range. As a result, final averages for 2016 should be slightly lower than averages for the period running from December to September. But, as noted above, we are still on track to see a very significant jump above the 2015 end atmospheric temperature totals.

Climate Impacts from Added Global Heat Continue to Worsen

All this extra heat in the system will work to worsen the already extreme climate and weather events we are seeing. Potentials for droughts, floods, heatwaves and wildfires will increase. High atmospheric moisture loading will continue to pump up peak storm potentials when storms do form. Added heat will tend to accumulate at the poles more than in the tropics or middle latitudes. As a result, upper-level wind patterns will likely continue to see more anomalous features along a worsening trend line. Ice in all forms will see stronger heat forcings overall, adding risk that both land and sea ice melt rates will increase.

impacts-to-the-cryosphere

(In the mid-2010s, Earth entered a temperature range averaging 1 C above pre-industrial levels. Such temperatures begin to threaten key climate impacts like permafrost thaw, 3-4 meters of sea-level rise from West Antarctic Ice Sheet melt, risk of up to 80 percent mountain glacier loss, complete Arctic sea ice loss during summer, and 6-7 meters of sea level rise from Greenland melt. In the near 1 C range, risks of these impacts, though a possibility, remain somewhat lower. But as temperatures approach 1.5 and 2 C above pre-industrial levels, risks rise even as West Antarctic glacial melt and polar ocean acidification start to become serious factors. Image source: Solving the Climate Stalemate.)

At 1 to 1.3 C above 1880s levels, we should see a quickening in the rate of sea-level rise. How much is uncertain. However, this temperature range is very close to peak Eemian Stage levels when oceans were around 15 to 25 feet higher than they are today. The current rapid rate of temperature change will also continue to have worsening impacts on creatures who are adapted to inhabit specific climate zones. The rapid rise in global temperatures is forcing an equally rapid movement of climate zones toward the poles and up mountains. This affects pretty much all life on Earth and unfortunately some species will be hard-pressed to handle the insult as certain habitats basically move off-planet. This impact is particularly true for corals, trees and other species that are unable to match the rapid pace of climate zone motion. We have already seen very severe impacts in the form of mass coral and tree death the world over. Warming in the 1 to 1.3 C range also provides an increasing ocean stratification pressure — one that has already been observed to increase the prevalence of ocean dead zones and one that will tend to shrink overall ocean vitality and productivity.

Fierce Urgency For Climate Action

Despite all these negative impacts, we are still currently outside the boundary of the worst potential results of climate change. Stresses are on the rise from various related factors, but these stresses have probably not yet reached a point of no return for human civilization and many of the reefs, forests, and living creatures we have grown to cherish. Rapid mitigation through a swift transition away from fossil fuels is still possible. Such a response now has a high likelihood of successfully protecting numerous civilizations while saving plant and animal species across the planet. That said, at this point, some damage is, sadly, unavoidable. But the simple fact that we are now starting to face the harmful consequences of a century and a half of fossil fuel burning is no excuse for inaction. To the contrary, the beginning of these harms should serve as a clarion call for our redoubled efforts.

Links:

NASA GISS

NOAA ESRL

NOAA El Nino

Climate of Gavin

The Truth About Climate Change

COP 21: Why 2 C?

Solving the Climate Stalemate

Hat tip to Kevin Jones

Hat tip to Florifulgurator

NASA Map Shows Large Portions of Greenland are Melting from Below

During recent years, as human fossil-fuel emissions have forced the Earth to warm, observations of Greenland’s surface has indicated a rising rate of melt. What has been less well-observed is melt rates beneath the ice and near the ice base. This is important because the pooling of water beneath the great ice sheet can help speed its movement toward ocean outlets, along with accumulating heat at the base of the ice — which can also quicken the pace of overall melt.

A new scientific study headed by NASA researchers has developed one of the first comprehensive maps of melt along Greenland’s basal zone, where the ice contacts the ground surface. What they have found is that large portions of Greenland are melting from below:

Greenland basal thaw map

(New, first-of-its-kind map shows extensive melt along the Greenland ice sheet base. Melt in this region is a sign that heat is building up beneath the ice as well as on top. Image source: NASA.)

This mapping study found that wide expanses of northern Greenland and pretty much all of southern Greenland are now experiencing melt at the ice sheet base. As the interior of Greenland has a cracked-bowl topography — with land bowing down into a central trough and numerous furrows connecting the ice sheet with the ocean — understanding where liquid water and heat are pooling at the bottom of the ice sheet will help scientists to get a better idea of how Greenland’s glaciers will respond to human-forced warming.

Joe MacGregor, lead study author and glaciologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland recently noted:

“We’re ultimately interested in understanding how the ice sheet flows and how it will behave in the future. If the ice at its bottom is at the melting-point temperature, or thawed, then there could be enough liquid water there for the ice to flow faster and affect how quickly it responds to climate change.”

Geothermal Melt, Ice Sheet Heat Accumulation, and Climate Change

Melt along the base of the Greenland ice sheet has long been influenced by heat welling up from or trapped near the Earth’s surface. The heavy, thick ice sheet densely packs the ground and rocks under it, which generates and amplifies geothermal hot-spots beneath Greenland. In addition, the ice creates a kind of insulating layer which locks that ground heat in. As a result, the bottom of the ice sheet is often tens of degrees warmer than its top.

Alone, this blanketing effect is enough to generate some melt along the bottom of Greenland. But now that the surface is melting more and more, heat transport from the ice surface to the bottom via liquid water funneling down to pool below is a more common occurrence.

Subglacial lake recharges due to surface melt Greenland

(Recharge of subglacial lake by surface melt near the Flade Isblink ice cap is an example of how surface melt can interact with basal melt, driving the formation of water at the ice sheet base. Image source: Nature.)

The way this heat transfer works is that rising temperatures over Greenland form more extensive surface lakes and melt ponds during the increasingly warm summers (and sometimes briefly during other periods). Often, the meltwater will find a crack in the ice and flow down to the ice interior. Sometimes the water remains suspended in the middle layers between the surface and the ice sheet base as a kind of heat bubble. At other times, the water will bore all the way down to the ground where it can form into pools or subglacial lakes.

At Flade Isblink in northeastern Greenland, such a filling of a subglacial lake was observed during the 2011 and 2012 melt years. As Greenland warms, such instances are likely to become more common. In this way, melt at the surface can add to the amount of heat trapped below the ice sheet — forming a kind of synergistic melt process.

The new NASA study helps our understanding of how such a process might unfold by showing the current extent of subsurface melt. The study combined physical models with observations to create this larger picture of bottom melt, telling a dramatic story of the opening period of human-forced Greenland melt, in which sub-surface melt is already very extensive.

Conditions in Context — The Level of Atmospheric Greenhouse Gasses is Now About Equal to Where They Were When the Greenland Ice Sheet First Formed

In context, the Greenland ice sheet is the largest repository of land ice remaining in the Northern Hemisphere. Covering a vast region of 1,710,000 square kilometers and rising up to 3 kilometers high at its tallest point, this ice sheet contains fully 2,850,000 cubic kilometers of ice. If all this ice melted, it would raise the world’s sea levels by around 7.2 meters (nearly 24 feet).

This enormous mountain of ice astride Greenland began to form about 11 to 18 million years ago during the Middle Miocene climate epoch. Back then, atmospheric carbon dioxide ranged from 405 to 500 parts per million. This decline from earlier, higher CO2 concentrations was allowing the world to cool enough to begin to support glacial ice in this region (around 4 C warmer than 1880s values).

Greenland_Mass_Balance

(Losses of Greenland mass from the surface zone have been accelerating during recent years. This loss has primarily been driven by human-forced warming of the Arctic. Though the North Atlantic Oscillation can generate melt variability by driving warm air flows toward or away from Greenland, the overall long-term driver has been a rapid warming of the Arctic region due to fossil-fuel emissions. Though we have a pretty good understanding of surface melt, our understanding of melt at the base of the ice sheet and heat accumulation there is less complete. Such an understanding may help us to predict future ice sheet behavior. Image source: Skeptical Science.)

Back then, Greenland’s ice was far smaller, far less extensive. It was a baby ice sheet that would grow into a behemoth as the Miocene cooled into the Pliocene — when CO2 levels fell to around 390 to 405 ppm — and then into the various ice ages and interglacials that followed (featuring atmospheric CO2 in the range of around 180 ppm during ice ages and around 275 ppm during interglacials).

Now, human fossil-fuel burning has put the ice sheet in a great global-warming time machine. With atmospheric CO2 levels hitting Middle Miocene ranges of 407.5 ppm at Mauna Loa this year, an accumulation of enough heat to significantly melt large portions of Greenland’s ice is a very real and growing concern. Exactly how that melt may unfold is still a big scientific mystery, but the risks are growing along with the heat and the new NASA basal melt study helps to shed a little light.

Links:

First Map of Thawed Areas Under Greenland Ice Sheet

NASA Maps Thawed Areas Under the Greenland Ice Sheet

Recharge of Subglacial Lake by Surface Melt Water in Northeast Greenland

Pliocene

Middle Miocene

Greenland Ice Sheet

Hat tip to Colorado Bob

Large Sections of Greenland Covered in Melt Ponds, Dark Snow

Over the past couple of days, temperatures across the Greenland Ice Sheet have really ramped up. The result has been a pretty significant mid-to-late season melt pulse. According to NSIDC, nearly 40 percent of the ice sheet surface has been affected by surface melt during recent days. And Greenland ice mass balance appears to have also taken a hit.

This surface melt pulse is, arguably, best portrayed in the satellite imagery:

Greenland Melt July 20

(Large section of Western Greenland near the Jackobshavn Glacier experiencing significant surface melt on July 20, 2016. Image source: LANCE MODIS.)

On July 20th, this approximate 300 x 70 mile swath of Western Greenland shows a number of distinct strong melt features. Near the interior edge of the melt zone we notice the light blue coloration indicative of widespread and general surface melt. From the satellite, this bluing gives the impression of a thin layer of surface water covering a widespread area of the ice sheet. But it is more likely that the blue tint comes from a plethora of small melt ponds and rivers that blend together in the lower resolution satellite shot to lend the impression of ubiquitous water coverage.

Large Melt Ponds, Dark Snow Over Western Greenland

Further in, we notice the darker blue swatches that indicate large melt ponds. Some of these ponds are quite extensive — measuring 1/4 to up to 1 mile in length. Ponds of this size tend to put a lot of pressure on the Greenland surface and can pretty quickly bore down into the ice sheet’s depths and interior. The water then either becomes locked in the ice — forming a kind of subglacial lake — or flows to base regions of the glacier where it can lubricate the ice — causing it to speed up.

Large Melt Ponds Dark Snow Western Greenland

(Close up satellite shot shows 1/4 to 1 mile long melt ponds, general melt ponding and a darkened Greenland Ice Sheet. Image source: LANCE MODIS.)

Still closer to the ice edge we find greatly darkened patches of ice. Darkening occurs when ice melt reveals and thickens past layers of ice sheet dust and soot accumulation. Each year, winds carry dust from land masses and soot from fires — which now, due to rapid Earth warming, burn more frequently over the Arctic and near-Arctic — to the ice sheet where it accumulates. This darker material is then covered by the annual layers of snowfall. If enough snow and ice melts, the yearly layers of dust and soot accumulation can concentrate into a gray-black covering. Such a covering is clearly visible in the July 20 satellite imagery above.

According to Dr. Jason Box, as much as 5.6 percent of the Greenland Ice Sheet was covered by this darkening, which he calls Dark Snow, as recently as 2014. Darkening of the Greenland ice sheet can accelerate melt as it reduces the ice sheet’s ability to reflect the sun’s rays — resulting in more overall heat absorption.

Substantial Northeastern Greenland Melt Also Visible

Zachariae Surface Melt Darkening

(Zacharie Isstrom Glacier in Northeastern Greenland shows significant melt in July 20 satellite shot. Image source: LANCE MODIS.)

Though surface melt and darkening is quite extensive along the southwestern flank of Greenland, toward the north and east, widespread surface melt, ponding and ice darkening is also visible over sections of the Zachariae Glacier. Here, in a far northern section of Greenland that borders the Arctic Ocean, we find an approximate 100 x 20 mile region of melting and darkening ice. Note the tell-tale bluing and dark gray patches visible in the above image.

For this region, ice has tended to experience more melt during recent years as sea ice within the Fram Strait and Greenland Sea has receded. This has revealed more darker ocean surfaces which, in turn, has absorbed more incoming solar radiation resulting in increased warming for this section of Greenland.

Conditions in Context — Human-Forced Warming Pushing Greenland to Melt Faster

Overall, Greenland melt is this year less extensive than the record 2012 melt season. However, the current mid-to-late season pulse has forced a big melt acceleration that may result in melt that exceeds 250 billion tons of ice loss for 2016 (or the average over recent years). In the pretty near future, continued high global temperatures and additional warming due to human fossil fuel emissions will almost certainly push Greenland to melt at a faster pace.

To this point, the Earth has now warmed by more than 1 C above Preindustrial temperatures. And a range of 1-2 C warming from this baseline in past climate eras such as the Eemian resulted in a 10-20 foot rise in world ocean levels. We’re in this temperature range now. So that’s pretty bad news for sea level rise — to which Greenland now contributes enough melt to lift seas by about 0.75 mm every year. The only real questions at this point are how fast will that already substantial melt accelerate, and will we halt fossil fuel burning swiftly enough to slow it down.

Links/Attribution/Statements

LANCE MODIS

The National Snow and Ice Data Center

Greenland Surface Mass Budget

These Stunning Photos of Greenland’s Dark Snow Should Worry You

The Dark Snow Project (please support)

Hat tip to Andy in San Diego

Hat tip to DT Lange

Scribbler-sponsored note on Trump:

Trump Chooses Climate Change Denier as Energy Advisor

Greenland’s Contribution to Sea Level Rise Doubled During 2011-2014 — Larger Melt Pulses on the Horizon

According to a new report, the Greenland Ice Sheet lost one trillion tons of water due to melt during the four-year period from 2011 through 2014. That’s about double the typical rate of loss during the 1990s through mid-2000s. Subsequently, Greenland’s contribution to sea-level rise also doubled. As a result, Greenland alone contributed 0.75 mm of sea-level rise every year during the 2011 to 2014 period.

(The above video briefly explains the findings of a new scientific study indicating a doubling in the rate of Greenland melt during 2011 through 2014.)

Bear in mind, the study focuses on Greenland only. Those numbers don’t include thermal expansion from the world’s warming oceans. Nor do they include an increasing amount of melt from Antarctica. Nor do they include large volumes of melt coming from the world’s rapidly disappearing mountain glaciers. Together, all of these in total are pushing sea levels higher by around 4 mm per year during the 2011 through 2016 period. That’s about 1 mm more per year than the 1993 to 2009 period. But the greater additional contribution appears to be coming from melting glaciers in Greenland and Antarctica.

The new Greenland Study found that melt averaged around 250 billion tons per year over the four-year period. This included a single melt year, 2012, in which Greenland contributed about half a trillion tons of melt water. The massive 2012 melt was spurred by high Greenland surface temperatures during summer which resulted in spiking surface melt rates during June, July, and August. At the time, a powerful high pressure system focused heat across the ice sheet which caused most of the surface area of Greenland’s glaciers to experience melt.

According to the study:

During 2011–2014, Greenland mass loss averaged 269 ± 51 Gt/yr. Atmospherically driven losses were widespread, with surface melt variability driving large fluctuations in the annual mass deficit. Terminus regions of five dynamically thinning glaciers, which constitute less than 1% of Greenland’s area, contributed more than 12% of the net ice loss. This high-resolution record demonstrates that mass deficits extending over small spatial and temporal scales have made a relatively large contribution to recent ice sheet imbalance.

In other words, melt at the margins of the ice sheet and large surface melt pulses during brief periods were the primary contributors to increasing melt rated during the study period.

Annual Mass Loss from Greenland and Antarctica

(Annual mass losses from Greenland and Antarctica are accelerating. This results in increasing rates of global sea level rise. While mass loss in Antarctica has recently primarily been driven by basal melt, surface melt has been the chief contributor to Greenland mass loss. In addition, the highly variable nature of surface mass loss along with its tendency to create brief, intense melt pulses is some cause for concern. Image source: Charting Ice Sheet Contributions to Global Sea Level Rise.)

The study found that surface melt rates were highly variable and dependent upon weather — with a strongly negative North Atlantic Oscillation contributing to conditions that enhanced melt during 2012. In this case, it appears that natural variability is beginning to be pushed by human-forced warming into a phase where certain years will preferentially further enhance Greenland melt. To this point, the tendency for large surface melt spikes was found to have increased during recent years. In contrast to Antarctica, where warming oceans contact glacial cliff faces and ice shelf undersides to accelerate melt, in Greenland, surface melt appears to currently be playing a bigger role in driving melt acceleration.

Surface melt can produce odd and unstable patterns of melt ponding and runoff over large ice sheets like Greenland. And as Greenland continues to warm due to human-forced climate change, an increasing risk of glacial outburst floods can be the result. The highly variable nature of surface melt is also a concern. In other words, overall warming can produce extreme, if brief, periods of warmth over Greenland that produce disproportionately large melt spikes. In this case, 2012 should not be seen as an outlier, but as the first of many future strong surface melt years — ones that will almost certainly surpass that year in melt intensity unless human-forced warming is somehow brought to a halt.

Links/Attribution/Statements

A High Resolution Record of Greenland Mass Balance

Excellent Comment on the Paper By Slate writer Phil Plait

Charting Ice Sheet Contributions to Global Sea Level Rise

Glacial Outburst Flood

Hat tip to Colorado Bob

Coastal Cities, Critical Infrastructure Unprepared to Face the Rising Tides of Climate Change

Civitasthe latin word for city and the root word for civilization. Civilization, in other words, is a collection of component cities. And, by extension, any major threat to a large number of cities is a threat to civilization itself. Such is the case with human-forced climate change.

*****

It’s a sad fact that many of the hundreds of coastal cities around the world are living on borrowed time. Current greenhouse gas levels — topping out near 408 parts per million CO2 (and 490 parts per million CO2e) this year — will need to fall in order to prevent 1-3 C of additional warming and 25 to 60 feet or more of sea level rise over the coming decades and centuries. And even if we somehow dialed atmospheric CO2 and CO2e levels back to 350 ppm, it’s likely that we’d still see seas eventually rise by 10-20 feet over the long term due to already destabilized glaciers in places like Greenland or West Antarctica.

But with fossil fuel burning continuing at near record levels globally, and with many corporations and political bodies around the world dragging feet on greenhouse gas emissions cuts, the level of heat-trapping carbon held aloft in our airs will continue to rise for some time. These vastly irresponsible actions will further heat the atmosphere and ocean — melting a greater share of the world’s land ice and forcing seas to ultimately rise even more. If CO2e exceeds a range of 550 to 650 parts per million — which could easily happen even under so-called moderate rates of fossil fuel burning before the middle of the 21st Century — then all the land ice on Earth will be placed under melt pressure. And that vast sum of ice melt represents about 220 feet of sea level rise long term so long as the greenhouse gas melt and heat pressure remains.

Sea level rise AVISO July 2016

(Seas have been rising in concert with ocean warming and fossil fuel burning since the start of the 20th Century. At first, during the first half of the 20th Century, rates of rise were less than 1 mm per year. By the 1993 through 2016 period, sea level rise averaged 3.39 mm per year. And since 2011, the rate of rise appears to have steepened into the range of 4 to 6 milimeters per year. Image source: AVISO.)

Even more disturbing is the fact that in the geological past, glacial melt has not tended to process in a gradual, orderly fashion. Instead, initial gradual melt has, in deep history, often been punctuated by very large melt pulses as glacial systems rapidly succumbed to warming environments. And with human warming now proceeding at a pace about 20 times faster than the end of the last ice age, the risk for rapid melt has been greatly enhanced.

Despite continued snide claims by climate change deniers to the contrary — it really is a global emergency. One that includes difficult impacts now and a rising risk of far worse impacts to come. A very real kind of long emergency for human civilization and the natural world combined. One made no less worse by its current deceptively slow, if massive and inexorable, advance.

Hundreds of Cities Under Threat

Due to this threat posed by human-forced warming of the global climate system, cities that have lasted for hundreds or thousands of years now face a serious risk that they will ultimately be devoured by rising tides. Around the world, nearly half of the world’s approximate 4,000 cities with populations of greater than 100,000 people sit on or near the coastline, at elevations below 220 feet, or near bodies of water that are vulnerable to sea level rise. Under the continued pressure of human-forced warming on global ocean levels, a good number (5-10 percent) of these cities may begin to succumb to rising tides in as little as a 10-30 years. And, long term, over 30-300 year time frames, pretty much all are threatened if the world continues burning fossil fuels.

Greenland Glacial Melt

(Glacial melt, like from this pond-riddled and melt-darkened section of Greenland as seen on July 8 of 2016, threatens many coastal cities this Century. With human warming of the Earth atmosphere approaching 2 C, the threat of large glacial outburst flood events that rapidly push sea levels higher is rising. But even gradual sea level rise is already disrupting cities and the infrastructure that supports them. Image source: LANCE MODIS.)

New Orleans, London, Sydney, Shanghai, Los Angeles, New York, Alexandria, Amsterdam, Miami, Norfolk, Washington DC, and Toyko are just a handful of the major cities that are mostly low-lying or that contain large low-lying sections. And all are below the 220 foot sea level rise line that current levels of fossil fuel burning will begin to put into long-term play before mid-Century.

Infrastructure is the First Vulnerability

While complete inundation by rising tides is the ultimate issue, cities do not have to face such drowning to fall under threat. Water supplies, transportation nodes and arteries, food supplies, and energy production and distribution facilities all represent lynch-pins that, if disrupted, can take down a city’s ability to effectively function. And sea level rise often threatens many or all of these critical supports well before the problem of total inundation becomes an issue.

Miami, for example, now faces a combination of these threats due to the presently emerging early outlier effects of human-forced sea level rise. There, just one foot of rising tides since the early 1870s has now put 2.4 million of Miami’s residents and 1.3 million homes within 4 feet of the high tide mark. By 2015, that relatively minor sea level rise had increased tidal flooding by 50 percent. Roadways and neighborhoods were more frequently cut off by the rising waters — which prompted the election of Philip Levine as Mayor of Miami Beach and the implementation of his 400 million dollar project to elevate roads and add pumps.

The city’s water supply, provided by a fresh water aquifer running through porous limestone, is protected from ocean salt water intrusion by a fresh water barrier of canals. A mere six additional inches of sea level rise will render the current system both ineffective and vulnerable to over-topping due to heavy rainfall events.

Power Stations, Roads, and Airports

By 2030, Miami is expected to see between 6-10 more inches of sea level rise. By the end of this Century, it will probably see at least 6 feet — and that’s if we don’t pursue business as usual fossil fuel burning and if the world’s glaciers mostly behave themselves by not giving us a big, angry melt pulse in response to our insults. The result is that not only Miami, but the far-flung critical infrastructure that supports it is also under threat.

In this context, Miami’s airport is just 8 feet above the high tide line. The nearby Turkey Point Nuclear facility which provides energy to the city and a big chunk of South Florida is about 6 feet above the high tide line. And though its reactors are elevated by another 20 feet of concrete buttressing, this Century’s predicted sea level rise would flood its grounds and surrounding roadways — likely rendering it inoperable.

Nuclear Stations Sea Level Rise

(Long term inland extent of sea level rise under 2 C and 4 C warming scenarios for US East and Gulf Coasts puts 13 nuclear facilities in the firing line. And an unexpected melt pulse or powerful storms riding on the top of sea level rise present a risk of flooded reactors. Such an inland rush of waters would also drown scores of coastal US cities, cut off roadways, flood aquifers, inundate crops, submerge airports, and sink conventional power stations. Image source: Nuclear Regulatory Commission, National Geographic, Climate Central.)

In the US, nine nuclear power stations are located on the coast. Another 13 are vulnerable to sea level rise. These sites are located near the ocean or along ocean fed rivers. They are ultimately vulnerable to sea level rise spurred by 2 or 4 degrees Celsius worth of warming. Without a herculean effort to not only reduce greenhouse gasses, but to recapture them from the atmosphere, 2 C warming is already locked in (this Century or longer term). The 4 C number is possible by late this Century under business as usual fossil fuel burning and is possible long term (500 year time scales) under the continuous 490 ppm CO2e forcing now in place.

Many large coal and gas power plants which also require heavy flows of water to support their operations are located near the coast. Oil refineries, which rely on shipping are often very close to sea level. Many major roadways are vulnerable to cut-off from sea level rise. And an amazingly large number of key airports are below a 20 foot elevation.  A small sampling includes San Diego International Airport at 13ft in elevation, Santa Barbara — 10 feet, Vancouver –14 feet, Portland 20 feet, JFK — 13 feet, La Guardia — runway elevations between 7 and 21 feet, Reagan National — 13 feet.

New York Also Armoring Against Rising Tides

In the northeastern US, another city has recently had a harsh global warming wake-up call. About a foot of east coast sea level rise added to the approximate 13 foot storm surge of Hurricane Sandy to flood Staten Island and large sections of lower Manhattan. The local power station flooded — propelling the city into darkness even as the subway system drowned and one neighborhood filled with water and burned at the same time.

Post Sandy responses have resulted in a flurry of activity. Fully 60 billion dollars has been spent to rebuild and a good chunk of that has gone to making the city more protected against both storms and rising sea levels. High rises are now required to lift critical infrastructure such as water pumps and spare generators into the upper stories should lower levels flood. A big flood resiliency effort, starting with the 3 billion dollar construction of a 10 foot high, two mile long flood barrier in 2017, is underway. One that may buttress much of lower Manhattan behind a U shaped wall meant to deflect both rising tides and worsening storms.  And a new park now features hills up to 70 feet above sea level.

Post-Glacial_Sea_Level

(At the end of the last ice age, as global temperatures approached 2 degrees Celsius above previous averages, large melt pulses from Antarctica and Northern Hemisphere Ice Sheets forced seas to rise by as much as 10 feet per Century. Human-forced warming is currently about 20 times faster than warming at the end of the last ice age. Current rates of warming and greenhouse gas emissions threaten to generate a 2 C warming by or even before the middle of this Century. Large melt pulses forced by such conditions would put cities like New York under risk of rapid inundation. Image source: Post-Glacial Sea Level Rise.)

These efforts appear to be aimed at facing off against another 1 foot of sea level rise for Manhattan by 2030 and a North Atlantic Ocean that is increasingly riled by powerful storms due to warming related climate instabilities. New York is digging in for the fight of its life. And for good reason. 10 percent of US gross domestic product funnels through this city of 8.5 million and over 100 billion dollars worth of real estate now sits in a high risk flood zone.

But build and buttress as it might, New York is hopeless in the long term if we can’t somehow stop human carbon emissions soon. If we can’t somehow start to draw carbon out of the air. If we can’t do these things, then New York, Miami and thousands of other coastal cities will ultimately face 25 feet of sea level rise or much, much worse. And the far flung infrastructures that they rely on will all, increasingly, need more and more costly and involved protections before they too succumb to the rising tides.

Links/Attribution/Statements:

Rising Seas Threat to Miami

Miami Nuisance Flooding Up by 50 Percent

As Waters Rise, Miami Beach Builds Higher Streets

Miami Herald — Sea Level Rise

Nuclear Regulatory Commission

Sea Level Rise — Are Coastal Nuke Plants Ready?

Sea Level Rise Risk to Coastal Nuclear Plants

Can New York Be Saved in the Era of Global Warming?

Post-Glacial Sea Level Rise

New Park Built to Withstand Epic Storms

Global Cities Map

Ancient Civilization

Scientific hat tip to Dr. James Hansen

Scientific hat tip to Dr. Eric Rignot

Scientific hat tip to Dr. Jason Box

Hat tip to DT Lange

Hat tip to Scott

Hat tip to Genomik

Hat tip to Cate

The Greenland Summer Melt Season Just Started in April

12 Percent. That’s how much of Greenland’s surface experienced melt yesterday according to a report from DMI’s Polar Portal  as an unprecedented flow of warm, wet air slammed into its great ice sheets. 10 Percent. That’s how much of Greenland’s ice sheet surface is required to melt in order to mark an official start to the Summer melt season. Late May or early June. That’s when Greenland melt season typically begins.

In other words, a Greenland melt season that usually starts as May rolls into June and has never initiated before May 5th just began on April 11th of 2016. That’s 24 days ahead of the previous record set only six years ago and more than a month and a half ahead of the typical melt start. In other words — way too early. But in a rapidly heating world where monthly temperatures have now exceeded a range of 1.5 C above 1880s levels, we could well expect Greenland melts to begin earlier, end later, and encompass more and more of the ice sheet surface at peak melt during July.

 

Record Early Start to Greenland Melt Season

(Record early start to Greenland’s ‘Summer’ melt season occurred on April 11, 2016 according to reports from DMI’s Polar Portal.)

Yesterday’s new record early melt start occurred as extraordinarily warm temperatures in the range of 20-40 degrees Fahrenheit above average swept over southern, central and western Greenland. This flood of extremely warm temperatures for Greenland was accompanied by heavy rains and strong winds — gusting to gale or even hurricane force in some locations. In some areas, rain fell over the ice sheet itself. As recently as midday Tuesday, Dr. Jason Box — a prominent Greenland researcher — tweeted a report from a friend in Nuuk that the city was “close to drowning in water caused by rain and snow melt.”

Today, temperatures for the whole of Greenland — a 1.7 million square kilometer island containing enough ice to raise sea levels by more than 20 feet should it all melt — were measuring as high as 10.17 C above average (more than 18 F above average) with readings over much of northern and central Greenland spiking over 20 C (36 F) above normal (1980-2010) ranges. So it’s likely that Monday’s record early 12 percent surface melt will extend and possibly expand on through today (April 12).

Greenland 10 C Above Average Temperatures

(Extreme warmth over much of Greenland on April 12th is continuing a new record early start to melt season for this up to two mile high pile of ice. Image source: Karsten’s Climate Maps. Data Source: NOAA/NCEP/GFS.)

Over the coming week, temperatures across Greenland are expected to steadily fall back toward more normal ranges. However, it’s worth noting that much of the heat from this year’s record early melt spike will be baked into the ice — adding a kind of internal heat pressure as Spring gradually progresses into Summer.

During July of 2012, an unprecedented 95 percent of Greenland’s surface experienced melt. For 2016, unprecedented Arctic warming during Winter appears to have set the stage for a serious challenge to both 2012 Greenland and 2012 Arctic sea ice melt records. And with seasonal sea ice at or near new record lows even as Greenland is off to an amazingly early melt start, it appears that 2016 is now in a race to set a number of new benchmarks as Arctic ice continues its ominous and disruptive longer-term decline.

Links:

Warm, Southerly Winds Gust to Hurricane Force in Staggering Early Season Greenland Heatwave

Unusually Early Greenland Melt

Greenland Melt Season Started Nearly Two Months Early

Karsten’s Climate Maps

Dr Jason Box’s Twitter Feed

Hat Tip to Andy in San Diego

Hat Tip to Sidd

Hat Tip to TodaysGuestIs

Gale After Gale After Gale Dumped Two and a Half Feet of Rain Upon Scotland and Wales This Winter

Reports from the UK Met Office are in. And we can say now with confidence that the UK have never seen weather like what they experienced this Winter. It looks like a storm track super-charged by climate change really socked it to the region this year. That we’ve just passed a winter worse than the then record years of 2013 and 2014 — only two years on.

A Stormy New Climate State for the North Atlantic

For the UK and for North Atlantic weather stability in general, the sea surface temperature anomaly signature in the graphic below is bad news. The cool pool just south of Greenland (indicated by the swatch of pale blue) is a new climate feature. One that appears to be related to glacial ice melt outflow from Greenland.

North Atlantic Sea Surface Temperatures

(10 degree Celsius above average sea surface temperatures off North America in today’s ensemble sea surface temperature model graphic are just insanely warm. Ocean surface anomalies used to rarely exceed 2 degrees Celsius warmer than average. These spikes off North America are an indication that the Gulf Stream is backing up and that overturning circulation off Greenland is slowing down. Image source: RTG-SST/NCEP /US National Weather Service/Earth Nullschool.)

Such melt outflow tends to slightly freshen sea surface waters. Freshening waters keep more heat locked into the ocean’s depths. They tend to cool the surface waters. And they slow down an ocean overturning circulation that, in the North Atlantic, drives the flow of the Gulf Stream.

A slowing Gulf Stream delivers less heat to this zone even as it piles more heat up off the North American Coast. As a result, a warm west, cool east dipole tends to develop. In the cool region south of Greenland, unusually strong storms have developed more and more frequently — with a dramatic impact on UK weather. The storms feed on this temperature differential even as they have gorged on heat and moisture streaming northward in a meridional flow over Western Europe. The results this year were nothing short of record-shattering.

Hottest and Wettest

For England and Wales, with temperatures ranging about 2 degrees Celsius above average for December, January and February, 2015-2016 probably beat out 2007 and 1989 as the hottest Winter on record. Meanwhile, Wales and Scotland saw the most rainfall ever recorded — with totals for both regions hitting around 756 millimeters or about two and one half feet. That’s even more rainfall than the previous record stormy Winter of 2013 and 2014.

Yet one more Gale

(Yet one more gale sets up to hammer Ireland, the UK and Scotland by Thursday. Four months of ongoing stormy conditions appears set to continue through to at least mid-March. Image source: NOAA’s Ocean Prediction Center.)

These heavy rains set off severe floods and damaged homes, roads, and bridges throughout the UK with the worst damage focusing in on regions to the North. One heavy precipitation hot spot — Argyll — saw an extraordinary 1035 mm or 3.5 feet of rainfall over the three month period. The Met Office is quick to point out that though December, January and February were the wettest on record since 1910, heavy rainfall events began in November — resulting in what amounts to a relentless four month pounding as storm followed storm and flood followed flood.

And, it appears, this persistent and ongoing storm pattern has not yet changed. For the North Atlantic remains riled — setting up to hurl a new gale-force low at Ireland and the UK this week. With the weather pattern essentially stuck in stormy since November, folks from these regions have got to be asking — when’s it going to end? As storms continue to fire off in the dipole zone above, it appears it will likely last until at least mid-March.

Links:

The UK Met Office

NOAA’s Ocean Prediction Center

World Ocean Heartbeat Fading

RTG-SST/NCEP /US National Weather Service/Earth Nullschool

Winter of 2015/2016 Wettest on Record for Scotland

Mystery Deepens Around Greenland Cold Spot

Hat tip to Colorado Bob

Hat tip to TodaysGuestIs

Hat tip to Dan Combs

 

 

 

 

 

 

Rapid Acceleration in Sea Level Rise — From 2009 Through October 2015, Global Oceans Have Risen by 5 Millimeters Per Year

The evidence that a human-forced warming of the globe is hitting a much higher gear in terms of both added heat and ramping impacts just keeps streaming on in. Today, an update in the satellite monitor tracking global sea level rise provides yet one more ominous marker. The world’s oceans are rising at an unprecedented rate not seen since the end of the last Ice Age. A rate that appears to be rapidly accelerating.

Greenland Melt Zachariae Isstrom

(Surface melt visible across the Zachariae Isstrom Glacier in Greenland on July 20th of 2015. Melt like that occurring on this glacier has become more and more widespread over Antarctica and Greenland. It’s an ongoing heat accumulation in the world’s great ice mountains that is contributing to increasing melt water outflows into the rising world ocean system. Image source: LANCE MODIS.)

It’s a tough bit of evidence that the world is swiftly accumulating heat. For aside from atmospheric temperature readings, the rate of sea level rise is probably the best marker for how fast the world is warming. It’s a sign of heat build-up that’s thermally expanding the ocean. And, far more ominously, it’s a sign that the great glaciers of the world are starting to accumulate enough heat to go into a more and more widespread melt and destabilization.

Ocean Rise Begins with Ramp-up in CO2 Emissions

Ever since the Holocene climate era began about 10,000 years ago, ocean levels and shorelines have remained remarkably stable. At the close of the 19th Century, and in conjunction with a build-up of heat-trapping gasses in the atmosphere through the extraction and burning of fossil fuels, sea levels began a rise that would start to mark a departure from the stable coastlines human civilizations had enjoyed for so long.

hansen-sea-level-rise

(Global sea level rise has ramped higher and higher — an upward curve that follows increasing volumes of CO2 in the atmosphere and rising global temperatures. Image source: Dr. James Hansen.)

At first the rise in global waters, driven by a then slow accumulation of heat in the world ocean system, was slight and gradual. Beginning in 1870, and continuing on through 1925, sea levels across the world increased by about 0.8 millimeters per year. The increase was likely driven by heat accumulating in the atmosphere and then transferring to the surface waters of the oceans. From 1870 through 1925, atmospheric carbon dioxide levels had increased from around 280 parts per million to 305 parts per million — into a range about 25 parts per million above the typical interglacial peak CO2 level of the last 2 million years. A volume of heat trapping gasses that began to slowly upset the Holocene’s relative stability.

If scientists and researchers at the time were paying closer attention, they would have noted this mild but consistent increase in the height of global surface waters as the first hint that the human emission of greenhouse gasses was starting to alter the Earth environment. Sadly, it took many more decades to begin to understand the profound changes that were starting to take place.

The First Acceleration — 1925 to 1992

While climate science was still in its infancy during 1925, a human forced warming of the globe was starting to kick into higher gear. A signal of atmospheric warming since the 1880s was beginning to develop. Though unclear, it was becoming apparent that the airs of the world were building up heat. But the waters of the world were providing a strong signal that the Earth was accumulating that heat more and more rapidly.

Sea level rise, at that time driven by thermal expansion and by a later small but growing contribution from glacial melt, took its first leap higher. And from 1925 through 1992, the average rate of sea level rise more than doubled to 1.9 millimeters per year. It was a sign that the Earth was warming more and more rapidly and that the heat was showing up in still more thermal expansion of the world’s waters.

The Keeling Curve

(Globally, CO2 began to increase in the atmosphere starting with the widespread burning of coal in England during the 17th and 18th Century. As new fossil fuels like natural gas and oil were added to the mix and as fossil fuel based burning greatly expanded during the 19th, 20th, and 21st Centuries, concentrations of this key greenhouse gas sky-rocketed. By the decade of the 2010s, the rate of atmospheric greenhouse gas accumulation was about 6 times faster than at any time in the geological record. A human emission that, if it continues for just a blink in geological timescales, is the equivalent to multiple clathrate guns firing off at the same time. Image source: The Keeling Curve.)

During the same period, atmospheric greenhouse gasses increased from 305 parts per million in 1925 to around 350 parts per million (entering the bottom range of the Pliocene 2-5 million years ago) by 1992. This jump by 45 parts per million in just 67 years pushed the Earth’s climate well outside the range of past interglacials — exceeding the previous peak of 280 parts per million CO2 by more than 70 parts per million overall. Atmospheric temperatures, by 1992, had also increased into a range about 0.5 C above 1880s values.

We had started to enter a period where the context of the human-driven warming (primarily enforced by a monopolization of energy markets by fossil fuels) was being pushed far outside the range of the Holocene and into time periods tens of thousands to hundreds of thousands of years in the geological past. The Earth System, in other words, was entering a period of increasingly dangerous imbalance.

The Second Acceleration 1992 to 2009

During the 17 years from 1992 through 2009, atmospheric carbon dioxide levels rose by 40 parts per million to about 390 parts per million in total. That’s a rate of accumulation nearly four times faster than the entire period from 1925 through 1992. An accumulation that by 2009 had pushed the world into a climate context more similar to the warmest periods of the Pliocene of 2-5 million years ago, than of the geological epoch in which human civilization emerged and thrived. For the Holocene was then starting to look like some fond memory fading off into an increasingly murky and smoke-filled far horizon.

Rate of ocean heat uptake has doubled since 1997

(The amount of heat contained in the world ocean system has doubled since 1997. This raging ocean heat uptake has been fueled by a heat accumulation at the top of the atmosphere that is now equivalent to lighting off 5 hiroshima type bombs on the surface of the Earth every single second of every single day. 90-95 percent of this heat goes into the world ocean system. Image source: Dr PJ Gleckler — Industrial Era Ocean Heat Uptake Doubles. See Also: Skeptical Science.)

Rates of sea level rise again increased — hitting a ramp up to around 3 millimeters per year. More ominously, scientific studies were beginning to indicate that the Greenland Ice Sheet and West Antarctica were starting to significantly contribute to the rising waters. The great glaciers were showing their first signs of a mass seaward movement called a Heinrich Event. And with the world hitting 0.8 degrees Celsius above 1880s temperature values and rising, such an event was starting to look more and more likely.

Sea Level Rise at 5 Millimeters Per Year Since 2009

Now, by early 2016, with the world at 1.1 C warmer than 1880s averages and with CO2 levels likely to peak at around 407 parts per million this year, it appears that rates of sea level rise have again jumped markedly higher. For according to satellite altimetry data from AVISO, global sea levels rose by 36 millimeters from the end of 2009 through October of 2015. That’s an annual rate of around 5 millimeters per year and one far above the longer term range of 3.1 mm per year established from 1992 through 2012.

Sea level rise AVISO

(Global sea level rise as measured by satellite altimetry hits a noticeably higher ramp from 2009 through late 2015. Image source: AVISO.)

We can clearly see the departure from the trend line starting post 2011 in the above graph. And if we were to cherry pick that particular departure zone, the rate from trough-to-peak would be 7 millimeters per year. However, since a La Nina occurred during 2011-2012 and a record strong El Nino is occurring now, that particular trend line is probably a bit exaggerated. The reason being that La Nina tends to dampen rates of sea level rise through variable cooling and El Nino tends to spike rates of sea level rise as world surface waters warm during such events.

However, even when correcting for La Nina and El Nino variation, it appears that sea level rise since 2009 is tracking in a range of 4 to 5 millimeters each year — which is yet another significant departure from the trend. A rate that, if it were to further solidify, would be 5 to 6 times faster than initial rates of sea level rise at the start of the 20th Century or two and a half times faster than the sea level rise rates from 1925 through 1992.

Open water and no snow in south Greenland on February 2, 2016

(Open water and no snow in Southern Greenland on February 2 of 2016. Zero sea ice and no snow in southern Greenland during Winter is a strong sign that the island is falling deeper and deeper into the grips of a severe warming event. Image source: Greenland Today.)

Spiking rates of heat accumulation and related thermal expansion of the world’s oceans is likely playing a part in the current increase. But, all-too-likely, the numerous destabilized glaciers now rushing seaward — which in total contain at least enough water to raise seas by 15-20 feet — are also starting to add greater and great contributions. And, unfortunately, with global temperatures now pushing into a very dangerous range between 1 and 2 degrees Celsius above 1880s averages, we are likely to see more and more of these glaciers go into a rapid seaward plunge. It looks like we’ve already locked in a ramping rate of sea level rise for decades to come and at least 15-20 feet long term. But that pales in comparison to what happens if we keep burning fossil fuels.

Links:

AVISO Sea Level Rise

Climate Monsters We Want to Keep in the Closet

Greenland Glacier Rapidly Losing Mass

Dr PJ Gleckler — Industrial Era Ocean Heat Uptake Doubles

Skeptical Science

Collapsing Greenland Glacier Could Raise Seas by 1/2 Meter

Dr. James Hansen

Contribution of the Cryosphere To Changes in Sea Level

The Keeling Curve

LANCE MODIS

Greenland Today

Hat Tip to Catherine Simpson

Hat Tip to Wili

 

Did a January Hurricane Just Set off a Massive Greenland Melt Event in Winter?

This freakish Winter there’s something odd and ominous afoot.

We’ve seen unprecedented above-freezing temperatures at the North Pole coincident with record low daily sea ice extents. We’ve seen global temperatures hitting new, very extreme record highs. We’ve seen climate change related storms raging across the globe — flooding both the UK and the Central US, firing off record hurricanes during January in both the Pacific and the Atlantic — even as other regions swelter under record heat and drought.

Now, it appears that Greenland is also experiencing an unprecedented melt during wintertime.

image

(The remnants of hurricane Alex being pulled into a storm system just south of Greenland on Friday January 15, 2016. An event that then flooded both Baffin Bay and Western Greenland with warm, tropical air. At the same time, Greenland observers both noted what appears to be ice mass losses over Western Greenland as well as a possible large melt water outflow issuing from the Disko Bay area. Image source: Earth Nullschool.)

Greenland Melt During Winter

Greenland — the last bastion of major continental glacial ice in the Northern Hemisphere. An island archipelago dwarfed by great mountains of frozen water towering as high as two miles. Though the Arctic sea ice provides quite extensive coverage — in the range of millions of square miles — the great Greenland Ice Sheet contains the majority of the remaining frozen fresh water in the Northern Hemisphere. And though the extreme ongoing sea ice melt does not contribute to sea level rise, Greenland melt is another matter entirely. In total, if all of the Greenland Ice Sheet flooded into the world ocean, it would raise global sea levels by an average of 23 feet. Enough to inundate pretty much every coastal city in the world.

And Greenland is melting, pushing those sea levels higher. Contributing hundreds of cubic kilometers of melt water into the world ocean system every year since at least the middle of the first decade of the 21st Century. Creating an ominous ocean heat-conveyer that spreads fresh, cool water out at the surface even as it pulls deep, warmer water directly in toward the many glaciers whose towering faces plunge into the ocean itself.

During recent years, most of Greenland’s melt has occurred during the hot season of summer even as the ice sheet underwent re-freeze and a pseudo-recovery during Winter. Sure, net mass loss was in the range of hundreds of billions of tons each year. But we still had consistent and uninterrupted mass gain during Winter.

Unfortunately, with human-forced warming there was always a danger that, during Wintertime, we’d see an increase in melt pressure as well. At issue is the way in which greenhouse gasses fundamentally warm the atmosphere and oceans. Possessing the ability to re-radiate solar energy, greenhouse gasses have a greater impact on temperatures during times of darkness and during Winter. In other words, we’d expect nighttime temperatures to warm faster than daytime temperatures and we’d expect wintertime temperatures to warm faster than summertime temperatures. Perhaps more ominously, the oceans are very efficient holders of heat and are less impacted by seasonal variance than the lands. In other words, if the world’s oceans warm, they re-radiate much more heat back to the atmosphere and ice sheet during Winter than they do during Summer.

This kind of greenhouse gas warming is an assault on the winter season itself. It’s something we’ve seen in the frequent extreme polar warming episodes during recent years. One that this year generated a very odd and ominous period of above-freezing temperatures at the North Pole. But if there’s something even more odd than temperatures at the North Pole hitting above freezing during Winter, it’s an incident of substantial melt occurring over the Greenland ice sheets during what should be the coldest, darkest season.

January Hurricane Blows a Tropical Wind into the Arctic

Over the past few days, just such a major heat-up has been underway across a large section of Western Greenland. Warm winds flowing off the North Atlantic — driven by hurricane Alex’s merging with powerful lows south of Greenland — have roared up over the southern coastal ranges. Meanwhile, warm, tropical air has infiltrated northward over Baffin Bay. The net result is temperatures approaching 20-40 degrees Fahrenheit above average (16 to 22 C above average) over a broad region of Western Greenland.

Greenland Warm UpGreenland warm up temperature

(By Sunday, 15-36 F above average temperatures had come to dominate much of southern and western Greenland. This translated to near or above freezing temperatures over sections of the Jacobshavn Glacier. Image source: Climate Reanalyzer.)

Over the past few days, as indicated in this recent post by Jason Box, the region near Disko and Uummannaq Bays — both in Baffin Bay and along the coastal ranges — has felt the full force of this substantial warm-up. By today, a large section of the coastal offshore waters and a wedge of glacier-covered Western Greenland all experienced near or above-freezing temperatures. A very rare event for Greenland and Baffin Bay during wintertime and one that appears to have coincided with a possible large glacial melt water outflow from the Jackobshavn Glacier.

Spot temperature readings along the southern reaches of the Jacobshavn Glacier hit 1 C or 34 F today according to GFS measures. Meanwhile near freezing temperatures have dominated Niaqornat on Uummannaq Bay (forecast to hit 32 F on Tuesday). Ilulissat on Disko Bay is showing 36 F temperatures at 12:00 AM Monday and is forecast to hit 41 F on Tuesday, even as Nuuk (about 200 miles south of Ilulissat) is showing 40 F temperatures at 12:00 AM Monday. These are all extremely warm readings for Greenland during Winter.

Greenland Glacial Melt During Winter

Disko and Uummannaq Bays are notable in that they are the outflow zone of the Jackobshavn Glacier — one of the swiftest-melting glaciers on Greenland. Over recent years, it has been one of the primary hot-spots for summer Greenland ice mass loss. But during recent days, mass loss also appears to have occurred in this area.

Western Greenland Melting in January

(Western Greenland has shown surface mass losses during recent days as in this January 17 mass balance data provided by DMI.)

Dr Jason Box notes that surface mass balance totals have consistently shown up as negative over the past week in the DMI measure. A record that continued today. Though Dr. Box states that such a negative mass balance could simply be chalked up to wintertime sublimation, the consistent losses showing up in the monitor over the past seven days have coincided temperatures in a melt-inducing range.

In addition, Dr Box also indicates a disturbing flushing of ice away from both Disko and Uummannaq Bays occurring on January 16th. In the satellite shot, both sea ice and ice burgs are moved en-mass from the bays and on out into the waters of Baffin.

Large Melt Water Pulse From Jacobshavn?

Offshore winds could be the cause. But, again, the ice movement coincides with indications of mass loss over Greenland’s Western glaciers as well as a period of much warmer than normal, above-freezing temperatures.

Large meltwater pulse from Jacobshavn

(Did a huge melt water pulse issue from the Jacobshavn Glacier on January 16, 2016? Dr Jason Box appears to be concerned that it has. Image source: Dr. Jason Box.)

Perhaps more ominously, this widespread clearing of ice from these Arctic bays occurs in concert with what appears to be a large ice-calving event along the ocean-facing front of the Jacobshavn Glacier. In the above graphic by Dr. Jason Box (see more here), we see a large retreat of the glacier together with what looks like a major sediment outflow. Sediment hitting water in this way would be a sign that a very large volume of water had been expelled along the basal zones of the Jacobshavn. In addition, the ice itself appears to have been forcibly ejected. This apparent sediment flush, the concave bowing of sea ice away from Disko and Uummannaq and the inland recession of the calving face are all indicators that something terrible is afoot in Western Greenland.

A large flush of melt water coming from Greenland during Winter would, indeed, be that terrible thing. Something that now may become a more and more common feature of our age as Winter continues its ongoing retreat against a relentless assault by human greenhouse gas emissions.

 

Links:

What is Up in Disko-Uummannaq Bay, Greenland January 9-16

Mauri Pelto @ Realglacier

Earth Nullschool

Climate Reanalyzer

DMI

Hat Tip to Colorado Bob

Arctic Sea Ice Prepping For New Record Lows in 2016-2017?

It’s been a pretty rough Summer for Arctic sea ice. Rougher than one would expect when considering how rapidly Greenland is melting and given that the Gulf Stream appears to be slowing down.

Increased rates of Greenland melt, increased fresh water outflow from rivers into the Arctic Ocean, and increases in ice berg calving have provided more fresh water to the Arctic Ocean (which would tend to cool the ocean surface) and weakened the south-to-north heat transfer of the Gulf Stream. Under such conditions, we’d tend to expect more than a little rebound in Arctic sea ice coverage. What we instead saw was a brief bump in the sea ice area, extent and volume measures during 2013 and 2014.

As of September 2nd, less than two weeks shy of traditional melt season end, sea ice extent in the JAXA measure had hit second lowest on record (please also see Neven’s most recent comprehensive sea ice report for his take on near end season ice states).

image

(Japan’s sea ice monitoring facility finds Arctic extent values at second lowest on record for September 2, 2015. Image source: JAXA.)

It’s a trend well below the 2014 pseudo-recovery year. One that is now tracking just beyond the previously record-smashing 2007 trend line. The measure of 4.346 million square kilometers is about 60,000 square kilometers below 2007. And though still quite a bit higher than 2012, it’s a swing that pushes toward a somewhat unsettling reassertion of the long-term melt trend. A trend that since the 1970s has reduced late season sea ice coverage by nearly half.

Other measures, though slightly less pronounced than the JAXA monitor, also show significant departures below the pseudo-recovery years 2014 and 2013. The NSIDC extent measure places the 2015 melt season as roughly tied with 2007 as second lowest on record and a 4.586 million square kilometer coverage. Meanwhile, sea ice area is tracking the 2010 melt line at 6th lowest on record for the date at 3.322 million square kilometers — a substantial 370,000 (approximate) square kilometers below 2014 — in the Cryosphere Today measure.

Conditions in Context — Preparation for Another Record-Breaker in 2016 and 2017?

Given recent science and observations showing increased rates of Greenland melt, increased fresh water flows into the Arctic Ocean, and a slowdown of the Gulf Stream, North Atlantic Overturning Circulation, and a related development of a cool pool between Greenland and England, we should probably assume that the Arctic is now involved in a climate change feedback tug of war. On the one hand you have rising atmospheric greenhouse gas levels in the Arctic due to a combination of human emissions and a growing carbon feedback response from permafrost and seabed stores. This heat-trapping atmospheric witch’s brew couples with loss of sea and land ice albedo to push for a continued rapid Arctic warming. On the other hand, you have fresh water outflows interrupting some of the south-to-north heat transfer in the North Atlantic and keeping a lid on some of the ocean heat in the High Arctic and near Greenland.

Laptev Storm

(A storm churns through the Laptev Sea on September 3, 2015, hurling 25-35 mph winds and 6-10 foot seas at the nearby ice. Trends show that 2015 is likely to be a year of ice losses, with end summer area and extent values in the range 2nd to 6th lowest on record. Image source: LANCE MODIS.)

Adding to this volatile mix is a potentially record-shattering El Nino which will, over the course of the next two years generate an ocean and atmospheric heat pulse that will probably maximize in the Arctic come 2017. Since 2015 is seeing returns to sea ice area and extent values in the range of 2010, 2011, 2008 and previous record low year 2007, there appears to be a preparation for the Arctic to challenge 2012 record low values over the 2016-2017 time period. And if sea ice does hit new record low values during that period of heightened risk we can also expect the whip-lash melt response from Greenland to grow even stronger.

Links:

JAXA

NSIDC

To Compact or Not to Compact?

Cryosphere Today

LANCE MODIS

Gulf Stream Slowing Down

Human-Baked Baffin Bay Takes Biggest Bite Yet out of The Greenland Ice Sheet

You wouldn’t generally think of ocean temperatures in the range of 40 to 50 degrees Fahrenheit (5 to 10 degrees Celsius) as hot. But to the great sea-fronting glaciers of Greenland it may as well be boiling.

Greenland Ice Sheet in Hot Water

All it takes is 32 degree F (0 C) water to begin melting the ice. And for each 1 degree increase above that margin, melt rates will dramatically ramp higher. Though a typical summer will push ice to melt at the Greenland seafront ice edge, this year, especially near Baffin Bay, the melt pressure has been extraordinary.

Ever since late June, 40-50 degree F sea surface temperatures have dominated the ice edge zone. For most regions that’s temperatures in the range of 4-11 degrees Fahrenheit (2-6 C) above average. The kind of heat that really risks a rapid melt along the ice margin.

Above Normal Sea Surface Temperatures Near Greenland

(Sunday, August 16 sea surface temperature anomalies as provided by NOAA.)

A latent heat that sits at the surface, gnawing away at the ice, waiting for a fresh water flood. And when the fresh water does come, that hotter, saltier, heavier water is forced downward beneath the lighter fresh water outflow. At this point, the hotter waters are locked below the surface where they go to work eating away at the glacier base. Notably, the only region within Baffin Bay where we currently see cooler surface water is in the major glacier melt zone near Jakobshavn. It’s an indication that ice melt from a major glacier outflow there is cooling the surface waters even as it pulls the surface heat downward and toward the glacial base.

This glacial melt heat conveyor is the kind of process we are seeing more and more frequently near the great ice sheets as fossil fuel industry has continued its harmful emissions. And, it’s a process that, this week took a huge chunk out of one of the world’s fastest moving ice masses.

Huge Chunk of Jakobshavn Breaks Off

According to reports from The Arctic Ice Blog, the Jakobshavn glacier sent its biggest chunk of ice on record floating off into Baffin on August 16 of 2015. For a glacier that drains 6.5 percent of the Greenland Ice Sheet and that has been known to release icebergs the size of Lower Manhattan, that’s really saying something.

You can see this amazing and rather chilling calving event in action in the August 14 to August 16 satellite imagery comparison developed by Espen Olsen below:

Espen Jakobshavn

(Jakobshavn experiences what is likely it’s largest calving event yet on Sunday, August 16, 2015. Image source: Espen Olson.)

Here we see the ice-choked Baffin Bay waters rapidly surging inland and taking up more of the Jakobshavn’s traditional outflow channel. What we do not see in this image, but what clearly happened, was that an ice mass hundreds of meters tall and covering an area of about 12.5 square kilometers was shattered into flinders as warming ocean waters invaded the Greenland Ice Sheet. Waters that will deliver still more heat to the ice. Waters that seek for the very heart of Greenland — a below sea level basin topped with 2-3 kilometer tall mountains of ice.

Back in the 19th Century, the Jakobshavn Fjord was half full of grounded Greenland ice. A long tongue of the glacier extended on outward through the channel. As of 2015, the Fjord is now completely full of water and ocean-bound ice bergs. The ocean itself has begun to invade the much larger ice masses beyond the Fjord. The broader inland mass of the Jakobshavn Glacier which is now directly in contact with the rising seas (indicated as Jakobshavn Isbrae on the maps above and below).

Jakobshavn Melt Progression

(Warming waters from Baffin Bay have driven through the ice in the Jakobshavn Fjord and are now boring into the thicker ice masses of Jakobshavn Ibrae. An impact that has serious implications for global sea level rise. Image source: The Arctic Sea Ice Blog and Espen Olsen.)

The inland-retreating Isbrae itself is a vast field of giant ice sheets. Massive tilting escarpments of luminous ice that, in the current age of fossil fuel forced warming, often cup great 1-3 kilometer long melt ponds in their wildly varied topography. It’s a single region that, in total, may hold about 1.5 feet of global sea level rise locked away in a rapidly melting ice pack. And Jakobshavn is just one of many regions (together containing about 15-20 feet worth of sea level rise) that are currently undergoing rapid melt due to the invasions of warming ocean waters.

Links:

NOAA

The Arctic Ice Blog

Espen Olson

A-Team

LANCE-MODIS

Bermuda High No More — Global Warming Shoves North Atlantic Anticyclone Toward Azores

The semi-permanent weather patterns are all out of whack. The Aleutians Low has been shoved into Alaska and the Beaufort. The Pacific California High has shifted north and west to dominate the region previously claimed by the Aleutians Low. And the Bermuda High — a feature famous for directing tropical cyclones northward along the Atlantic Seaboard has packed its bags and fled north and east.

During the late summers of more stable climates, a strong high pressure system tended to form over the region of Bermuda. The high swept warm, moist air up off the Atlantic Ocean and over the Eastern Seaboard of the United States. The high was also a reliable governor of the movements of tropical cyclones — with the position of the high critical in determining whether these powerful summer storms would make landfall or rocket out to sea.

But this August, the Bermuda High is nowhere to be seen. Instead, it’s shifted more toward mid and north Ocean — closer to the Azores and the Flemish Cap.

image

(The Bermuda High can now also be counted among the growing number of climate change refugees as it emigrates to the Azores and the higher Latitudes of the North Atlantic. Image source: Earth Nullschool.)

In the above image, provided by Earth Nullschool, white denotes areas of high pressure and purple-to-red denotes areas of low pressure. The green circle in the image marks the position of the North Atlantic High in today’s GFS summary map. Note that the high is shifted more than 1,000 miles to the east and north. It sits at the base of a ridge that stretches well north of the Flemish Cap and then extends eastward to just south of Britain, Scotland and Ireland. Near Iceland, a powerful cyclone rages. A fickle storm that alternatively sets its sights along an arc from England to Svalbard.

How Human-Caused Warming Shoves the Bermuda High Northward

A semi-permanent high pressure system north of the Azores and a very stormy North Atlantic in the triangle between Greenland, Svalbard and England is not remotely a normal summer weather pattern. It’s instead a feature of a number of new ocean and atmospheric dynamics that are the upshot of human-caused climate change.

As equatorial heat embodied by the Hadley Cell expands outward from the lower Latitudes, the oceanic highs, including the Bermuda High, are shoved northward. This motion tends to also shift weather tracks into higher Latitude boundaries even as it, at first, enhances waviness in the Jet Stream. Near North America, we can see this dramatic weather alteration in the form of the Ridiculously Resilient Ridge over the Pacific and the Terribly Tenacious Trough over the Eastern Seaboard.

A second feature that influences the displacement of the North Atlantic High is the expansion of a cool pool of water to the south and east of Greenland. This cool pool is an upshot of the ongoing melt of the Great Greenland ice sheet. As fresh water spills out from Greenland’s glaciers it cuts off the northward propagation of the Gulf Stream even as it prevents bottom water formation. This shutting down of ocean circulation causes heat to build further south along the Eastern Seaboard of the United States and in the Caribbean and Gulf of Mexico. The lack of south to north heat transport combines with the expanding fresh water cap to prevent ocean heat ventilation at the surface in the North Atlantic. As a result, we see an expanding pool of cool water in this zone. A signature feature of both human caused climate change and of glacial melt in Greenland.

image

(Earth Nullschool temperature anomaly map focused in on the North Atlantic with near -5 C readings in an uncanny and freakish cool pool there. This is the mirror opposite of the Hot Blob in the Northeast Pacific. And, eerily enough, it is also a feature of overall global warming. Image source: Earth Nullschool.)

During recent years, we have seen more and more of this cool pool formation as both the Gulf Stream and bottom water formation in the North Atlantic slowed down due to fresh water outflows from Greenland. It’s an oceanic cool pool that forms a kind of atmospheric slot for the Bermuda High to slip north through. It also generates an unstable boundary zone between hot and cold waters and airs — a mechanism that generates very high potential energies for powerful storms cycling in a rough arc around Greenland (climate change driven storms of this kind were the subject of a recent paper by Dr. James Hansen.)

As glacial outflows from Greenland expand due to a continued forced economic dependence on fossil fuels and the dumping of their toxic, heat-trapping emissions into the atmosphere, we are likely to see the Bermuda High continue to shift north. It’s the first of many features that will tend to produce powerful atmospheric bomb-type storms in a great zone within the North Atlantic. Storms of an intensity we likely haven’t seen through all the 10,000 year period of the Holocene.

It is for this reason that the shift of the Bermuda High north and east should be viewed as an ominous atmospheric move. One that is preparatory to far worse weather to come — during a time when the old Bermuda High will, perhaps, be viewed with a kind of fond nostalgia. A gentler weather feature of a once far kinder climate.

Links:

Semi-Permanent Weather Patterns

Earth Nullschool

Global Forecast System Model

Hadley Cell

Ridiculously Resilient Ridge

Terribly Tenacious Trough

Warning From Scientists: Stop Fossil Fuel Burning or Age of Storms, Rapid Sea Level Rise is Coming Soon

November-Type Gales Hit England in August — Looks Like a Weird Atmospheric Response to El Nino + Climate Change May Be Unfolding

Atmospheric ENSO INDEX

(Atmospheric El Nino Index by WSI shows a very strong atmospheric response is unfolding. But long range weather maps, long range NOAA forecast shows an atypical pattern for El Nino. Image source: WSI.)

They say that a picture can paint a thousand words. How about a graph that exceeds 100 El Ninos? It may not jump out at you at first, but that’s what we’re looking at above.

This graph, provided by Weather Channel Affiliate WSI (and based on atmospheric data collected by NOAA) represents intensity of atmospheric response patterns to El Nino. Typically, this means cloudiness at the Central Pacific Equator, the propagation of near equatorial westerlies, atmospheric wave propagation in the Jet Stream, and storm track amplification. In other words, teleconnections.

On the left side of the above graph, we see positive and negative numbers indicating standard deviation correlation to an ENSO neutral state. Push into 2 standard deviation range either high or low and you’re getting about a typical El Nino or La Nina response from the atmosphere. And ever since June we’ve been in the 3 standard deviation or about top 10 percent of El Nino response range.

That’s a pretty strong ocean to atmosphere signal. But it pales in comparison to what’s being predicted. Looking ahead, the Euro weather model then pushes us all the way up to a 4 standard deviation event (or top 1 percent of atmospheric response rates) by early-to-middle August. This is an extreme response to El Nino. One that could have some amazing impacts come Fall, or possibly sooner (see North Atlantic storm discussion below), especially when we take into account some of the added impacts of human caused climate change. Should such a response emerge, both the US Southeast and Gulf Coast could be in for some extremely severe storms.

Trough

(A rather deep trough for Summer-time swings down through the Eastern US. Image source: Climate Reanalyzer.)

For the US, such a strong atmospheric response to El Nino forcings would tend to indicate a powerful trough digging in through the Eastern half of the country, even during summertime. And while we do see a rather strong trough for this time of year setting up over and extending down from the Hudson Bay region of Canada, we do not see an overall suppression of summer-time heat and potential for greatly increased precipitation that would typically occur under such a pattern, as yet.

Instead and somewhat oddly, the pattern has kicked energy out over the ocean — fueling the North Atlantic storm track and powerful oceanic cold core cyclones at a time when such events should be rare. Yesterday, a gale hammered Scotland and Ireland, kicking up seas west of England into a frenzy of 30 foot swells. To say this event is odd for summertime is a bit of an understatement. Sans tropical storms swinging north, the higher Latitude regions of the Atlantic are typically calm this time of year.

Winter-Type North Atlantic Gales During Summer

But living in typical times we are not. Greenland melt is ramping up. And so we see the start of a Heinrich Event-like cool pool in the North Atlantic. Call it a baby Heinrich or a precursor or whatever you like. But it’s there. And it’s anomalously cool. And it’s going to influence the weather regardless of whether we like it or not. It’s an event related to both fresh water flow into the North Atlantic and an associated decline in the strength of the Gulf Stream. This odd summer North Atlantic storm generation is then, perhaps, due to a teleconnection between the strong atmospheric signal of El Nino and the underlying signal of human-forced climate change. Such a teleconnection would tend to shift the El Nino related trough a bit eastward and result in an amplified North Atlantic storm track. Which is exactly what we are seeing.

image

(It looked like a North Atlantic winter storm. But this screen capture of 30 foot swells due to a powerful gale off England was taken late last night [August 3rd]. For those familiar with typical summer patterns for the North Atlantic this should be a moment that inspires head-scratching. One with an uncanny similarity to patterns predicted in a recent paper by Dr. James Hansen. Image source: Earth Nullschool.)

NOAA long range forecasts are also picking up the signal of powerful storm track intensification over the Gulf Coast and the Southeastern US. Such a prediction hints at a strong storm track running diagonally across the Atlantic from Florida to England and aligned with a trough edge running through that broader region. It’s a pattern that could put England in the firing line for severe winter storms yet again. For the US, the upshot is powerful storms slamming a region from Texas through the Carolinas from September through February. Florida, Coastal Georgia and the U.S. Gulf Coast are particularly hard-hit in the forecast. But we also shouldn’t rule out some strong bombs impacting the Mid-Atlantic region before they tear off across the ocean.

No Significant Drought Relief for California?

Sadly, the atmospheric response to El Nino is not pushing forecasts for a wet winter for the US West Coast. Monsoonal moisture hits the US Southwest during September and October, but barely touches California in the forecast. The moisture pattern then retreats eastward. Heat and dryness are particularly focused in the region of Washington, Oregon, Idaho and Montana. Abnormal warmth is also predicted to remain in place over Alaska.

NOAA November December January PrecipitationNOAA November December January Temperature

(NOAA long range forecast finds little drought relief for the US West Coast this winter even under the influence of a predicted powerful El Nino. Image source: NOAA CPC.)

This pattern appears to indicate that the NOAA models are calling for the Ridiculously Resilient Ridge and the hot Blob of water off the US West Coast to mostly remain in place. An overall very bad forecast considering El Nino’s predicted intensity and the currently indicated strength of atmospheric response. It may be that cooling in the North Atlantic associated with Greenland melt and Gulf Stream weakening is having such a powerful impact on the Jet Stream that El Nino cannot over-ride — instead solidifying the Pacific Ridge to Atlantic Trough fixed atmospheric wave and dumping its teleconnection influence into the firing range that the North Atlantic is steadily morphing into.

To this point, it’s worth noting that long range model forecasts of this kind can carry with them a rather high error bar. The ocean-atmosphere forcing of the predicted super El Nino will likely result in some rather dramatic wrenchings of the climate system. And for such an El Nino to fail to over-ride the West Coast block would have some very serious added impacts on down the line.

Links:

Weather Channel Affiliate WSI

Climate Reanalyzer

Warning From Scientists Stop Burning Fossil Fuels or Rapid Sea Level Rise, Age of Storms is Coming Soon

Earth Nullschool

NOAA CPC

(Please support publicly funded, non-special-interest based science, like the fantastic work provided by NOAA and NASA, without which this report and the reports provided by Climate Reanalyzer, Earth Nullschool, and WSI would not be possible.)

Greenland Melt Extent Breaks 50% on July 4; 2 Standard Deviation Line Shattered Yet Again

These days — in the age of the fossil-fueled hothouse — it’s never good news when a high pressure system forms over Greenland during Summer.

Human dumping of carbon into the atmosphere has forced warming over the last remaining great Northern Hemisphere ice sheet at a rate of about 0.5 degrees Celsius each decade. A constant rain of soot from human industry and from increasingly prevalent and intense Arctic wildfires has painted the ice sheet dark, lowering its ability to reflect 24 hours of incoming radiation from the Summer sun. And the result is that each Summer, when the skies clear and high pressure systems form over the ailing Greenland ice, you end up getting these huge surface melt spikes.

Greenland smoke

(Smoke from record Alaskan and Canadian wildfire outbreaks traverses Greenland and enters the North Atlantic on July 2 of 2015. Arctic wildfires are intensified by human-caused warming both through the mechanism of added heat and through the reintroduction of long sequestered carbon fuels through permafrost melt which aids in the initiation, intensification and extension of Arctic wildfire burn periods. In essence soil carbon in the form of thawed permafrost and related methane adds to boreal forest, tundra and bog as burn risks. Soot from these fires can then precipitates onto land and sea ice, reducing its ability to reflect the 24 hour Summer Arctic sun. Image source: LANCE MODIS.)

Generally a big melt spike can be defined as anything greater than 35 percent of Greenland ice surface area. And we’ve had quite a few of these abnormal events in recent years. The worst of which happened in mid Summer of 2012.

During late June and early July of that year, an extreme high amplitude Jet Stream wave generated very warm surface temperatures over the Greenland Ice Sheet. A very warm fog settled over the ice, eating away at it. By July 8th, more than 90 percent of the surface was melting — an event that hasn’t happened in Greenland for more than 100 years. June, July and August of 2013 and 2014 saw similar, though somewhat less intense, Greenland melt spikes. During those years the ice sheet experienced multiple days in which melt covered between 35 and 45 percent of its surface. And though these instances were not as intense as the unprecedented 2012 melting, they did traverse well beyond the 1981 to 2010 average line (an average that itself includes a rapid warming trend) to, in cases, exceed the upper 2 standard deviation margin.

Melting on Greenland surface 2014

(Record Greenland surface melt during 2012 compared to still strong surface melt years of 2013 and 2014. Image source: NSIDC.)

After record 2012 melt, surface melt for Greenland has remained abnormally high — indicating an increased likelihood that more near 100 percent surface melt summer days may not be too far off in the future. The post 2012 environment for Greenland has thus been a period of continued and heightened surface melt. One that appears to be in the process of building up to another big pulse.

50 Percent Melt Threshold Exceeded During July of 2015

The summer of 2015 marks a continuation and intensification of this ominous surface melt trend. After getting off to about an average melt start during April and May, June saw surface warmth build over the Greenland Ice Sheet with melt extents jumping to between 30 and 40 percent of surface area by mid-to-late month. Further warming coincided with massive Alaskan and Canadian wildfires injecting soot plumes into regional airspace and the building of a substantial high pressure ridge over Greenland. These factors helped enable further atmospheric and ice warming — shoving surface melt above the 50 percent line by July 4th.

Greenland melt extent 2015

(Major Greenland melt spike indicated on July 1-5 in the NSIDC surface melt extent graph. Image source: NSIDC.)

This puts 2015 Greenland surface melt in a range well above 2013 and 2014, with the first week of July already exceeding 2012 melt for that period.

Over the next seven days, models predict a larger warming of the overall Arctic environment even as a high pressure system and associated ridge remains entrenched across Greenland. This predicted weather pattern will tend to lock in significantly warmer than 20th Century average temperatures. That said, forecast highs do not yet indicate a substantial risk for a repeat of 2012’s near 100 percent surface melt. However, projected high temperatures do show some potential that melt percentages are likely to continue to range between 40 and 60 percent surface melt over coming days with the highest risk for melt spikes occurring on July 6th, 7th and 8th.

It is worth noting that we are now in the midst of a substantial Greenland melt spike, one that we’ll continue to monitor over coming days for further developments.

Links:

LANCE MODIS

NSIDC

Dark Snow

GFS Forecast Summary

Record Alaskan Wildfire Outbreak

Hat Tip to Wili

Hat Tip to Andy in San Diego

Hat Tip to Colorado Bob

Hat Tip to DT Lange

No Pause — NASA Shows Human Hothouse Maintaining Record High Temperatures for 2015

GISS Pulse

(What 2015 temperatures would look like on the annual graph if the +0.79 C departure maintained throughout the present year. Problem is, there’s at least some risk warming could intensify. Image from Tamino’s recent blog post which, justifiably, rips the fussy math of Anthony Watts and ‘friends’ into tiny little pieces.)

It’s an El Nino year. It’s a year in which global CO2 averages are hitting above 400 parts per million for the first time in at least 3 million years. And it’s a year in which CO2 equivalent values for all greenhouse gasses (including methane, nitrogen compounds and other exotic heat trapping gasses) that humans have emitted are nearing 485 parts per million.

Added together — the equatorial Pacific Ocean taking a break in its duties as atmospheric heat sink (El Nino) combined with the immense volume of heat trapping gasses human beings have now loaded into the atmosphere — it’s more than enough to force global temperatures into territory likely not seen since the Eemian interglacial period 150,000 years ago.

Temperatures Continue March into Eemian Ranges

And NASA GISS, in its monthly report, is showing global temperatures that are edging into the Eemian range. First, April of 2015 came in at 0.75 Celsius (C) hotter than NASA’s global 20th Century benchmark (0.95 C hotter than 1880). This represents the second hottest value for April on record in the entire 135 year climate record, coming in just a bit cooler than the 0.83 C departure for 2010. Meanwhile, hindsight adjustments have found that the January-through-March period was warmer than earlier indicated — with new departures hitting +0.76 (Jan), +0.80 (Feb), and +0.85 (Mar).

Combined, the average of these first four months is +0.79 C above 20th Century measures. Or about +0.99 C above 1880s values. This puts us well outside the context of the 10,000 year period beginning at the end of the last ice age (Holocene) and edges us into a range more typical to the Eemian. A time when sea levels were between 6 and 8 meters (20-25 feet) higher than today.

Polar Amplification and the Greenland Cool Pool

Looking at the global temperature anomaly map provided by NASA, we can see where much of this extra heat accumulated throughout April:

Global Temps NASA April 2015

(NASA GISS global temperature anomalies map for April of 2015. Image source: NASA.)

Here we find that polar amplification for the upper Northern Hemisphere latitudes was continuing to hit high marks. Broad south-to-north wind flows over central Asia drove a powerful warming spanning up from Lake Baikal in Russia, on through Central Siberia, up over the Yamal region and into the High Arctic. Average temperatures for the month in this zone ranged from 2 C to as high as 6.9 C above average. Another zone of extreme warmth sprawled out over Western North America and into the Beaufort and Chukchi Sea regions. There, temperatures ranged between 1-4 C above 20th Century averages.

Other notable warm regions included the Equatorial Pacific — showing a band of 1-2 C departures in association with a developing El Nino — and the West Antarctic Peninsula, which saw heating in the range of 2-4 degrees Celsius above average for most of the month.

Overall, most of the globe showed above average readings with cool pools relegated to isolated regions. In particular, the distribution of cool temperatures near Greenland is somewhat disturbing. It’s an indication of increased glacial melt outflows from Greenland ice sheets into the North Atlantic. It’s also a validation of climate model analysis of human-caused global warming — which indicated cooling near Greenland due to a combination of ice sheet and ocean responses to heating the Earth-Ocean System. The ocean response — a dangerous slowing of Atlantic thermo-haline circulation — was also identified in a recent paper by Rahmstorf.

Zonal anomalies April of 2015

(NASA Latitudinal temperature anomalies again shows strength of Northern Hemisphere polar amplification. Image source: NASA.)

NASA zonal anomalies also continue to validate climate model predictions for human-caused warming. Here we find the predicted extreme polar amplification — more rapid warming of the Northern Hemisphere polar zone than the rest of the world — clearly indicated. There, in the 60-90 North Latitude zone we find temperatures ranging from 1-3.5 Celsius above the 20th Century global average. A rate of warming far exceeding any other region.

All other Latitudinal zones show about a +0.75 C above average temperature departure. The first noted exception is the heat sink in the Southern Ocean (at -0.5 to +0.5 C in this measure) which continues to uptake atmospheric heat, transfer it to the middle ocean and, by Ekman pumping through storm action, deliver it exactly where it is least needed — along the basal regions of various melting Antarctic ice shelves. The second is marked by a zone of March-April storm intensification along the Antarctic Continent and Southern Ocean boundary centering at 75 degrees South (-0.5 to -1 C).

Conditions in Context

Overall, temperatures at +0.99 degrees Celsius above 1880s averages for the first four months of 2015 should be cause for concern. We still have El Nino ramping up in the Pacific. And with some models showing the event could be quite powerful, the added boost to global heating we are seeing now could well ramp higher later this year. In addition, we are entering an Arctic melt season that is showing some risk of pushing Arctic sea ice into new record lows — at least early in the melt season. Such an event would further tilt the globe toward record heat by reducing ice-based light and heat reflectivity in the Arctic at times of 24 hour sunlight (May through July).

As such, there is risk that already record warming seen since 2014 and into 2015 could continue and, potentially, ramp higher through the end of this year.

Links:

NASA GISS

Standing on the Shores of Disaster

A Faustian Bargain on the Short Road to Hell

Catch 22 No 1

Steaming Equatorial Pacific Sees Winds Blowing Toward Monster El Nino

World Ocean Heartbeat Fading

Global Sea Level Rise Going Exponential? New Study Records Big Jump in Ocean Surface Height

From about a thousand years ago through to the mid 19th Century, global sea levels remained remarkably stable. Together with overall global temperatures, sea surface heights stayed at about the same levels until the late 1800s. At that time, an initiation of large-scale burning of oil, gas and coal dumped heavy volumes of greenhouse gasses into the atmosphere. The Earth System began to warm and seas began a slow upward climb.

Hansen sea level rise

(Global sea level rise since 1870. Image source: Dr. James Hansen.)

At first, the pace of sea level rise was minor — only hitting about 0.8 mm per year. But then, by around 1925, the rate of sea level rise more than doubled to 1.9 mm per year. The oceans, which at first only slowly accumulated heat, began a long term warming which eventually extended through almost every depth and region. This pace maintained until about 1992 when the oceans again hit a higher rate of rise at around 3.1 mm per year — a pace that then included a small but ominously growing portion of glacial melt.

Now, it appears that global warming is again pushing sea levels to rise even faster. As, over recent years, a number of ominous indicators pointed toward yet another surge in ocean surface levels.

In south Florida, the pace of  sea level rise at local tidal gauges, by last year, had gone exponential. Along the U.S. East Coast, a sudden jump in sea level during recent years was blamed on a slowing down of the Gulf Stream due to freshwater melt pulses hitting the North Atlantic.

All over the world’s frozen regions, the great land glaciers — especially in Greenland and Antarctica — have been destabilizing. Melting, cracking, and clamoring as their gargantuan, mountain-like forms assembled in an ever-speeding march to the seas. This great rush of freshwater melt and ice is already causing an ocean-threatening slow-down of Atlantic circulation. And in the Southern Ocean surrounding Antarctica an ominous bulge of water near the southern polar zone became an indicator of an increasing rate of melt from some of the largest glaciers on Earth. A bulge that was 2 centimeters higher than the global average along melting and thawing Antarctic shores.

Global Sea Level Rise On Upward Curve?

Recently, the global sea level rise measure — AVISO — also took an unsettling leap. With satellite captures of the world ocean showing a strong surge in sea level rise throughout 2014 and into 2015. A spike that displays vividly as a hockey-stick like jog at the tail end of the measure below:

Aviso sea level rise

(Big spike in sea level rise plainly visible in the AVISO measure. Image source: AVISO.)

It’s an upward jump representing nearly a 1 centimeter spike in the rate of sea level rise over the past six months.

By itself, this jump in sea level would be something to worry over. But new findings paint an even starker picture. For a recent study, headed by Shuang Yi and published on April 30 in Geophysical Research Letters provides evidence that, since 2010, annual rates of global sea level rise have shown a strong uptick. The study, entitled An Increase in the Rate of Global Mean Sea Level Rise Since 2010, notes:

The global mean sea level (GMSL) was reported to have dropped 5 mm due to the 2010/11 La Niña and have recovered in one year. With longer observations, it is shown that the GMSL went further up to a total amount of 11.6 mm by the end of 2012, excluding the 3.0 mm/yr background trend. A reconciled sea level budget, based on observations by Argo project, altimeter and gravity satellites, reveals that the true GMSL rise has been masked by ENSO-related fluctuations and its rate has increased since 2010. After extracting the influence of land water storage, it is shown that the GMSL have been rising at a rate of 4.4 ± 0.5 mm/yr for more than three years, due to an increase in the rate of both land ice loss and steric change.

In short, the study finds an average rate of sea level rise of 4.4 mm per year, or 30% faster than the annual rate from 1992 to 2009, during the period of 2010 to 2013. For these, more rapidly rising, sea levels the study identifies clear causes. The first is an increasing rate of land ice loss. The second is what is termed as ‘steric change’ — a scientific phrase that both identifies ocean thermal expansion due to warming combined with changes in ocean salinity, which also impacts sea surface height.

The April 30 study did not include the more recent sea level rise spike now showing up in the AVISO measure. So, at least for now, sea levels do appear to be sliding up some rather dangerous curves.

Hitting the More Difficult Rates of Sea Level Increase

Such a jump has stark implications for sea level by end century. A 4.4 mm per year rate of rise would equal just less than half a meter of increased sea level within one Century. This compares to the previous rate of rise which would have resulted in a 1 foot global jump within a one hundred year span.

A jump of this kind was, however, predicted with sea level rise by end of this Century expected to hit between 0.5 and 1 meters of increase in the IPCC measure and between 5 and 6 feet in US Coast Guard studies (most studies find a range between 3-9 feet for this Century). The 4.4 mm per year increase is rather ominous in that it already puts annual rates of rise in the IPCC mid-range. An early ramp up with fully eight and a half decades left to go in a Century that will certainly see substantial further increases in global heat accumulation.

Composite

(South Florida 6 meters of sea level rise before [left frame] and after [right frame]. Note that second image is an artist’s rendering based on flood analysis showing what a 6 meter sea level rise would look like for South Florida, should it occur. Image source: Tropical Audobon Society.)

Many planners use the IPCC measure or even more conservative indicators to prepare for sea level rise at their city, county and state shores. And the fact is these indicators may fall well short of reality at the coastlines. A stark circumstance that will become more and more difficult to manage as time moves forward.

Overall, a 2010 ramping in the rate of sea level rise is a bit soon. Similar further jumps leading up to potential worst case 1-4 cm per year levels would initiate a combination of dangerous impacts including untenable rates of rise for coastal regions, severe shocks to ocean circulation systems and overall ocean health, and potentially very dangerous impacts to the world’s weather. To this point Hansen’s paper entitled ‘Greenland Ice Sheet Mass Loss, Exponential?‘ is well worth a (re)read.

Similar Climate Conditions Saw 20 Meter Surges in Sea Level Due to Glacial Melt

With current greenhouse gas levels now in the range of 400-405 parts per million coinciding with substantial jumps in glacial melt and sea level rise, it may be worth taking a look back at times in the geological past when atmospheric heating conditions were similar to those seen today. The last time heat trapping gasses were seen at such high concentrations was at the height of the Pliocene warming 3-5 million years ago. That time saw temperatures in the range of 2-3 degrees Celsius warmer than Holocene averages. It was also a geological period that saw Antarctic and Greenland melt events that pushed seas up to 20 meters higher.

We are exceeding maximum Pliocene atmospheric CO2 thresholds at this time (well exceeding if you count in a 485 CO2 equivalent forcing from all greenhouse gasses added by human beings). And we will almost certainly enter Pliocene warming levels this century. So the melt pressure we are putting on the world’s ice sheets is likely to at least be in the 20 meter range for the (hopefully) longer term.

Links:

An Increase in the Rate of Global Mean Sea Level Rise Since 2010

AVISO

Dr. James Hansen

For Miami, Sea Level Rise Has Already Gone Exponential

An Extreme Sea Level Rise Event Along the Northeast Coast of North America

World Ocean Heartbeat Fading

Antarctic Sea Levels Rising Faster Than the Global Rate

IPCC Sea Level Rise

Tropical Audobon Society

Greenland Ice Sheet Mass Loss, Exponential?

20 Meter Sea Level Rise 5 Million Years Ago

Hat tip to Colorado Bob

Hat tip to Wili

World Ocean Heartbeat Fading? ‘Nasty’ Signs North Atlantic Thermohaline Circulation is Weakening

Scientists call it Atlantic Meridional Overturning Circulation (AMOC). But we may as well think of it as the heartbeat of the world ocean system. And when that heartbeat begins to slow down, we’d best sit up and start paying attention:

(New video produced by climate hawk Peter Sinclair and featuring top scientists Stefan Rahmstorf, Michael Mann, and Jason Box, issues warnings about an observed disruption to ocean circulation due to water freshening in the North Atlantic. This is the kind of work I mentioned last week in my KPFA interview. The kind that should be showing on major network news every single night. Since that probably won’t happen, I urgently ask you to spread this video, together with its critical information, as far and as wide as possible.)

Global Warming Poses Risk to Ocean Circulation, Life Support

For nearly three decades now, prominent climate scientists have been warning policymakers that salt and heat driven circulation of the world ocean system (called thermohaline — thermo for heat and haline for salt) could be disrupted by cold water outflows from Greenland. There, in the North Atlantic, salty, dense, ocean water issuing from the tropics along the Gulf Stream begins to cool. The heavier water, burdened with salt, sinks to the bottom in the North Atlantic. This sinking, in turn, drives a massive ocean conveyer belt. It delivers colder, oxygenated water to the deep ocean. It dredges less oxygen rich bottom waters to the surface where they can be reinvigorated. And it drives this ocean revitalizing train of currents through every major corner of the world ocean.

A disruption of this ocean water mixing machine would ripple through the world oceans like a gunshot to a vital circulatory organ, reducing oxygen levels throughout the whole ocean system, and greatly reducing the oceans’ ability to support life. It would be a major shift toward a stratified, less life supporting ocean, and one step closer to the nightmare ocean state called a Canfield Ocean (named after its discoverer — Dr. Donald Canfield).

Warmer, salty water cooling and sinking in the North Atlantic is an essential cog in the wheel of this massive ocean water overturning machine. It has also been described (as Dr Box notes in the video above) as the Achilles Heel of global ocean circulation.

But I like to think of it more as the world ocean’s beating heart. The reason is that any disruption of the overturning process in the North Atlantic basically kills off a life-giving circulation to the entire world ocean system.

Cooling in Exactly the Wrong Place

AMOC Temperature Trend

(Linear temperature trend from 1900 through 2013 produced by Stefan Rahmstorf in his new study. Note the anomalous cool pool just south of Greenland. That’s exactly the kind of temperature signature you don’t want to see. One that is indicative of cold, fresh water outflows from Greenland interfering with North Atlantic and World Ocean Circulation. Also see: RealClimate.)

Now, a new 2015 report headed by Dr. Stefan Rahmstorf finds that the world ocean system is cooling in exactly the wrong place — the North Atlantic just south and east of Greenland. This cooling is an indicator that a high volume outflow of cold, fresh water is entering this region of ocean. A cold, fresh outflow that comes directly from the melting glaciers of Greenland itself. A cooling and freshening that creates a physical block to salt water down welling in the North Atlantic. The kind of block that can directly disrupt the Gulf Stream and the rest of ocean circulation on down the line.

Dr Rahmstorf explains the findings of his study in his notes at RealClimate:

The North Atlantic between Newfoundland and Ireland is… the only region of the world that has defied global warming and… cooled. Last winter [this region] was the coldest on record – while globally it was the hottest [such period] on record. Our recent study (Rahmstorf et al. 2015) attributes [ anomalous North Atlantic cold water] to a weakening of the Gulf Stream …, which is apparently unique in the last thousand years.

It happens to be just that area for which climate models predict a cooling when the Gulf Stream System weakens (experts speak of the Atlantic meridional overturning circulation or AMOC, as part of the global thermohaline circulation). That this might happen as a result of global warming is discussed in the scientific community since the 1980s – since Wally Broecker’s classical Nature article “Unpleasant surprises in the greenhouse?” Meanwhile evidence is mounting that the long-feared circulation decline is already well underway. (emphasis and a little clarity added)

To Dr Rahmstorf’s point that the North Atlantic was experiencing a Gulf-Stream threatening record cold while the world was under a pall of record warmth, we need only look at NOAA’s Land-Ocean temperature anomalies map for the winter of 2014-2015 below:

NOAA land ocean temperatuer anomalies

(NOAA Land Ocean temperature anomalies map for 2014-2015 shows extraordinary record cold pool of water south of Greenland in a record warm world. The smoking gun for large glacial outflow and thermohaline disruption in the North Atlantic. Image source: NOAA via ClimateCrocks and MeltFactor.)

Other Concerns Regarding North Atlantic Cooling

Unfortunately, an expanding pool of cold, fresh water in the North Atlantic is not just a threat to ocean health. It also represents a zone of anomalous cold in a region surrounded by atmospheric and ocean warming. As such, it represents a zone of likely expanding atmospheric instability — one involved in the shift of the cold center of circulation from the polar zones and more toward Greenland and Canada. Parcel to the kinds of weather disruptions that have been described in the theories of Dr. Jennifer Francis and during some of the later works of Dr. James Hansen (alluded to in The Storms of My Grandchildren).

As such, cold water bleeding from the great glaciers of Greenland not only poses a threat to ocean circulation, it also poses a risk for generating significant disruptions to atmospheric winds and related weather as well. Ones that could set off increasingly intense storm events in the Northern Hemisphere similar to what was seen for the US Northeast this winter (but likely worsening with time) and the extraordinarily powerful barrage of storms hitting England during the winter of 2013-2014.

Dr. Hansen in his Greenland Ice Sheet Loss: Exponential? paper warned of the potential for continent-sized frontal storms packing the strength of hurricanes under some rapid Greenland melt scenarios by mid-century.

Hollywood dramatizations aside, this is more than enough real world weather and climate trouble to pose serious cause for concern. And as Dr. Rahmstorf, Peter Sinclair, Dr. Jason Box and Dr. Mann allude to the header video — the policy makers were warned well in advance.

Links:

A Nasty Surprise With the Greenhouse

What’s Going on With the North Atlantic?

Exceptional 20th Century Slowdown in North Atlantic Overturning Circulation

Unpleasant Surprises in the Greenhouse

NOAA

MeltFactor

Greenland Ice Sheet Loss: Exponential?

Linking Weird Weather to Rapid Warming in the Arctic

Canfield Ocean

Hat tip to Today’s Guest Is…

Greenland’s Late August Rain Over Melt Ponds is a Glacial Outburst Flood Hazard

Glacial melt ponding on steep ice faces. Above freezing temperatures for an extended period. Storms delivering rainfall to the glacier surface.

These three events are a bad combination and one that, until recently, we’ve never seen before for Greenland. It is a set of circumstances directly arising from a human-driven warming of the great ice sheet. And it is one that risks a highly violent and energetic event in which melt ponds over-top and glaciers are flushed and ripped apart by surges of water rushing for scores of miles over and through the ice sheet. Major melt pulse events called glacier outburst floods that can result in catastrophically large volumes of water and broken ice chunks issuing from the towering, melting glaciers of Greenland and Antarctica.

It’s a risk we face now, as the circumstances driving the risk of such an event are present today.

Rain over Ice on August 21, 2014

Over the past four days a high amplitude wave in the Jet Stream and coordinate domes of high pressure over Greenland have delivered well above average temperatures for the great Northern Hemisphere ice sheet. Near and just to the east of the Jakobshavn glacier on the West Coast of Greenland, temperatures have ranged between 5 and 10 degrees Celsius above average.

Greenland Temperatures August 21Rain over Greenland Melt Ponds on August 21, 2014

(GFS temperature and rainfall analysis for Greenland on August 21, 2014. Note the above freezing temperatures and rainfall over the region of the Jacobshavn Glacier for today. Image source: University of Maine’s Climate Reanalyzer.)

What this means is a persistence of average temperatures in the range of 34-40 degrees (F) over large sections of Greenland’s Jakobshavn glacier. Melt level readings over a region that has now experienced ongoing surface ponding for more than 60 days.

But these warm temperatures, providing yet more heat forcing to melt the ice, aren’t the only extreme weather factor for the Jakobshavn glacier today. For today has brought with it a warm, wet over-riding airmass emerging from Baffin Bay and the Atlantic Ocean to the south. The warm air, coming into contact with the cooler glacier air is condensing and disgorging a series of rainstorms, dumping above-freezing water into the Jakobshavn’s already swelling pools.

Some of these effects are directly visible in the LANCE MODIS satellite imagery provided by NASA.

Glacial melt ponds are indicated in the satellite shot below by light-to-dark blue splotches on the glacier surface. Shallow surface melt ponding and pooling is indicated by a thin skein of light blue. In the left frame below, you can see the extensive and large melt ponds in the region of the Jakobshavn Glacier on August 18, 2014. For reference, the largest of these ponds are between 2 and 4 kilometers across. Also note the pale blue color of the ice near the larger ponds, indicating extensive smaller ponds in the region.

In the right frame, we have today’s LANCE-MODIS satellite shot. You will note that the entire frame is covered by cloud but that you can still see the blue undertone of the melting glacier below the rain-bearing clouds.

Melt Ponds, Jakobshavn August 18Rain over Melt Ponds

(LANCE MODIS satellite shot of the Jakobshavn Glacier on August 18 [left frame] and August 20 [right frame]. Note the widespread melt ponds and blue ice indicating smaller ponds over the glacier structure. Image source: LANCE MODIS.)

Assessing Glacial Outburst Flood Risk

Some day, as Greenland continues to warm under the human heat forcing and as more hot air invasions ride up over the ice sheet, a period of warmth followed by rainstorms may well set off a major outburst flood event. The water content in melt ponds over the glacier may well be far greater than what we see now and a series of over topping events, starting higher on the ice sheet and magnifying toward the ice sheet base, would set of a chain of events leading to such a flood.

Risks for this kind of event today may well be moderate to low. The glaciers at this point are craggy and much of the flood waters shunt through holes in the ice to water pockets or to the glacier base. But eventually, as the glacier contains more water through subsequent years of melt, flooding and damming will be more prevalent throughout the ice sheet. And so risks will likely be on the rise.

Other than similar events occurring in the Himilayas, we don’t really have much of a context by which to judge risk for large Greenland outburst flood events. We do know that melt ponding is now quite extensive in this region and we do know that the glacier itself is rather unstable — moving with rapid speed toward the ocean and containing pockets of melted water from past melt pond formation over the last two decades.

For today, I’m pointing out the current rainfall over ice and melt ponding event as part of a larger and dangerous trend, one that is likely to play a primary role in the pace and violence of Greenland melt going forward.

zodiac on greenland melt pond

(Photograph of a zodiac on the surface of one of Greenland’s very large melt ponds. Image source: Earth Observatory.)

Links:

University of Maine’s Climate Reanalyzer

LANCE MODIS

The Glacial Megaflood

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